1 /*-------------------------------------------------------------------------
4 * POSTGRES C Backend Interface
6 * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
7 * Portions Copyright (c) 1994, Regents of the University of California
11 * $PostgreSQL: pgsql/src/backend/tcop/postgres.c,v 1.411 2004/05/19 19:39:27 momjian Exp $
14 * this is the "main" module of the postgres backend and
15 * hence the main module of the "traffic cop".
17 *-------------------------------------------------------------------------
27 #include <sys/socket.h>
30 #include <sys/select.h>
36 #include "access/printtup.h"
37 #include "access/xlog.h"
38 #include "catalog/pg_type.h"
39 #include "commands/async.h"
40 #include "commands/prepare.h"
41 #include "commands/trigger.h"
42 #include "libpq/libpq.h"
43 #include "libpq/pqformat.h"
44 #include "libpq/pqsignal.h"
45 #include "miscadmin.h"
46 #include "nodes/print.h"
47 #include "optimizer/cost.h"
48 #include "optimizer/planner.h"
49 #include "parser/analyze.h"
50 #include "parser/parser.h"
51 #include "rewrite/rewriteHandler.h"
52 #include "storage/freespace.h"
53 #include "storage/ipc.h"
54 #include "storage/pg_shmem.h"
55 #include "storage/proc.h"
56 #include "tcop/fastpath.h"
57 #include "tcop/pquery.h"
58 #include "tcop/tcopprot.h"
59 #include "tcop/utility.h"
60 #include "utils/guc.h"
61 #include "utils/lsyscache.h"
62 #include "utils/memutils.h"
63 #include "utils/ps_status.h"
64 #include "mb/pg_wchar.h"
75 const char *debug_query_string; /* for pgmonitor and
76 * log_min_error_statement */
78 /* Note: whereToSendOutput is initialized for the bootstrap/standalone case */
79 CommandDest whereToSendOutput = Debug;
81 /* note: these declarations had better match tcopprot.h */
82 sigjmp_buf Warn_restart;
84 bool Warn_restart_ready = false;
87 /* flag for logging end of session */
88 bool Log_disconnections = false;
90 LogStmtLevel log_statement = LOGSTMT_NONE;
92 /* GUC variable for maximum stack depth (measured in kilobytes) */
93 int max_stack_depth = 2048;
101 /* max_stack_depth converted to bytes for speed of checking */
102 static int max_stack_depth_bytes = 2048*1024;
104 /* stack base pointer (initialized by PostgresMain) */
105 static char *stack_base_ptr = NULL;
109 * Flag to mark SIGHUP. Whenever the main loop comes around it
110 * will reread the configuration file. (Better than doing the
111 * reading in the signal handler, ey?)
113 static volatile bool got_SIGHUP = false;
116 * Flag to keep track of whether we have started a transaction.
117 * For extended query protocol this has to be remembered across messages.
119 static bool xact_started = false;
122 * Flags to implement skip-till-Sync-after-error behavior for messages of
123 * the extended query protocol.
125 static bool doing_extended_query_message = false;
126 static bool ignore_till_sync = false;
129 * If an unnamed prepared statement exists, it's stored here.
130 * We keep it separate from the hashtable kept by commands/prepare.c
131 * in order to reduce overhead for short-lived queries.
133 static MemoryContext unnamed_stmt_context = NULL;
134 static PreparedStatement *unnamed_stmt_pstmt = NULL;
137 static bool EchoQuery = false; /* default don't echo */
140 * people who want to use EOF should #define DONTUSENEWLINE in
143 #ifndef TCOP_DONTUSENEWLINE
144 static int UseNewLine = 1; /* Use newlines query delimiters (the
148 static int UseNewLine = 0; /* Use EOF as query delimiters */
149 #endif /* TCOP_DONTUSENEWLINE */
152 /* ----------------------------------------------------------------
153 * decls for routines only used in this file
154 * ----------------------------------------------------------------
156 static int InteractiveBackend(StringInfo inBuf);
157 static int SocketBackend(StringInfo inBuf);
158 static int ReadCommand(StringInfo inBuf);
159 static void start_xact_command(void);
160 static void finish_xact_command(void);
161 static void SigHupHandler(SIGNAL_ARGS);
162 static void FloatExceptionHandler(SIGNAL_ARGS);
163 static void log_disconnections(int code, Datum arg);
166 /* ----------------------------------------------------------------
167 * routines to obtain user input
168 * ----------------------------------------------------------------
172 * InteractiveBackend() is called for user interactive connections
174 * the string entered by the user is placed in its parameter inBuf,
175 * and we act like a Q message was received.
177 * EOF is returned if end-of-file input is seen; time to shut down.
182 InteractiveBackend(StringInfo inBuf)
184 int c; /* character read from getc() */
185 bool end = false; /* end-of-input flag */
186 bool backslashSeen = false; /* have we seen a \ ? */
189 * display a prompt and obtain input from the user
194 /* Reset inBuf to empty */
196 inBuf->data[0] = '\0';
204 * if we are using \n as a delimiter, then read characters
207 while ((c = getc(stdin)) != EOF)
213 /* discard backslash from inBuf */
214 inBuf->data[--inBuf->len] = '\0';
215 backslashSeen = false;
220 /* keep the newline character */
221 appendStringInfoChar(inBuf, '\n');
226 backslashSeen = true;
228 backslashSeen = false;
230 appendStringInfoChar(inBuf, (char) c);
239 * otherwise read characters until EOF.
241 while ((c = getc(stdin)) != EOF)
242 appendStringInfoChar(inBuf, (char) c);
252 * otherwise we have a user query so process it.
257 /* Add '\0' to make it look the same as message case. */
258 appendStringInfoChar(inBuf, (char) '\0');
261 * if the query echo flag was given, print the query..
264 printf("statement: %s\n", inBuf->data);
271 * SocketBackend() Is called for frontend-backend connections
273 * Returns the message type code, and loads message body data into inBuf.
275 * EOF is returned if the connection is lost.
279 SocketBackend(StringInfo inBuf)
284 * Get message type code from the frontend.
286 qtype = pq_getbyte();
288 if (qtype == EOF) /* frontend disconnected */
291 (errcode(ERRCODE_PROTOCOL_VIOLATION),
292 errmsg("unexpected EOF on client connection")));
297 * Validate message type code before trying to read body; if we have
298 * lost sync, better to say "command unknown" than to run out of
299 * memory because we used garbage as a length word.
301 * This also gives us a place to set the doing_extended_query_message
302 * flag as soon as possible.
306 case 'Q': /* simple query */
307 doing_extended_query_message = false;
308 if (PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
310 /* old style without length word; convert */
311 if (pq_getstring(inBuf))
314 (errcode(ERRCODE_PROTOCOL_VIOLATION),
315 errmsg("unexpected EOF on client connection")));
321 case 'F': /* fastpath function call */
322 /* we let fastpath.c cope with old-style input of this */
323 doing_extended_query_message = false;
326 case 'X': /* terminate */
327 doing_extended_query_message = false;
328 ignore_till_sync = false;
332 case 'C': /* close */
333 case 'D': /* describe */
334 case 'E': /* execute */
335 case 'H': /* flush */
336 case 'P': /* parse */
337 doing_extended_query_message = true;
338 /* these are only legal in protocol 3 */
339 if (PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
341 (errcode(ERRCODE_PROTOCOL_VIOLATION),
342 errmsg("invalid frontend message type %d", qtype)));
346 /* stop any active skip-till-Sync */
347 ignore_till_sync = false;
348 /* mark not-extended, so that a new error doesn't begin skip */
349 doing_extended_query_message = false;
350 /* only legal in protocol 3 */
351 if (PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
353 (errcode(ERRCODE_PROTOCOL_VIOLATION),
354 errmsg("invalid frontend message type %d", qtype)));
357 case 'd': /* copy data */
358 case 'c': /* copy done */
359 case 'f': /* copy fail */
360 doing_extended_query_message = false;
361 /* these are only legal in protocol 3 */
362 if (PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
364 (errcode(ERRCODE_PROTOCOL_VIOLATION),
365 errmsg("invalid frontend message type %d", qtype)));
371 * Otherwise we got garbage from the frontend. We treat this
372 * as fatal because we have probably lost message boundary
373 * sync, and there's no good way to recover.
376 (errcode(ERRCODE_PROTOCOL_VIOLATION),
377 errmsg("invalid frontend message type %d", qtype)));
382 * In protocol version 3, all frontend messages have a length word
383 * next after the type code; we can read the message contents
384 * independently of the type.
386 if (PG_PROTOCOL_MAJOR(FrontendProtocol) >= 3)
388 if (pq_getmessage(inBuf, 0))
389 return EOF; /* suitable message already logged */
396 * ReadCommand reads a command from either the frontend or
397 * standard input, places it in inBuf, and returns the
398 * message type code (first byte of the message).
399 * EOF is returned if end of file.
403 ReadCommand(StringInfo inBuf)
407 if (whereToSendOutput == Remote)
408 result = SocketBackend(inBuf);
410 result = InteractiveBackend(inBuf);
416 * Parse a query string and pass it through the rewriter.
418 * A list of Query nodes is returned, since the string might contain
419 * multiple queries and/or the rewriter might expand one query to several.
421 * NOTE: this routine is no longer used for processing interactive queries,
422 * but it is still needed for parsing of SQL function bodies.
425 pg_parse_and_rewrite(const char *query_string, /* string to execute */
426 Oid *paramTypes, /* parameter types */
427 int numParams) /* number of parameters */
429 List *raw_parsetree_list;
430 List *querytree_list;
434 * (1) parse the request string into a list of raw parse trees.
436 raw_parsetree_list = pg_parse_query(query_string);
439 * (2) Do parse analysis and rule rewrite.
441 querytree_list = NIL;
442 foreach(list_item, raw_parsetree_list)
444 Node *parsetree = (Node *) lfirst(list_item);
446 querytree_list = nconc(querytree_list,
447 pg_analyze_and_rewrite(parsetree,
452 return querytree_list;
456 * Do raw parsing (only).
458 * A list of parsetrees is returned, since there might be multiple
459 * commands in the given string.
461 * NOTE: for interactive queries, it is important to keep this routine
462 * separate from the analysis & rewrite stages. Analysis and rewriting
463 * cannot be done in an aborted transaction, since they require access to
464 * database tables. So, we rely on the raw parser to determine whether
465 * we've seen a COMMIT or ABORT command; when we are in abort state, other
466 * commands are not processed any further than the raw parse stage.
469 pg_parse_query(const char *query_string)
471 List *raw_parsetree_list,
474 if (log_statement == LOGSTMT_ALL)
476 (errmsg("statement: %s", query_string)));
478 if (log_parser_stats)
481 raw_parsetree_list = raw_parser(query_string);
483 /* do log_statement tests for mod and ddl */
484 if (log_statement == LOGSTMT_MOD ||
485 log_statement == LOGSTMT_DDL)
487 foreach(parsetree_item, raw_parsetree_list)
489 Node *parsetree = (Node *) lfirst(parsetree_item);
490 const char *commandTag;
492 if (IsA(parsetree, ExplainStmt) &&
493 ((ExplainStmt *)parsetree)->analyze)
494 parsetree = (Node *)(((ExplainStmt *)parsetree)->query);
496 if (IsA(parsetree, PrepareStmt))
497 parsetree = (Node *)(((PrepareStmt *)parsetree)->query);
499 if (IsA(parsetree, SelectStmt))
500 continue; /* optimization for frequent command */
502 if (log_statement == LOGSTMT_MOD &&
503 (IsA(parsetree, InsertStmt) ||
504 IsA(parsetree, UpdateStmt) ||
505 IsA(parsetree, DeleteStmt) ||
506 IsA(parsetree, TruncateStmt) ||
507 (IsA(parsetree, CopyStmt) &&
508 ((CopyStmt *)parsetree)->is_from))) /* COPY FROM */
511 (errmsg("statement: %s", query_string)));
514 commandTag = CreateCommandTag(parsetree);
515 if (strncmp(commandTag, "CREATE ", strlen("CREATE ")) == 0 ||
516 strncmp(commandTag, "ALTER ", strlen("ALTER ")) == 0 ||
517 strncmp(commandTag, "DROP ", strlen("DROP ")) == 0 ||
518 IsA(parsetree, GrantStmt) || /* GRANT or REVOKE */
519 IsA(parsetree, CommentStmt))
522 (errmsg("statement: %s", query_string)));
528 if (log_parser_stats)
529 ShowUsage("PARSER STATISTICS");
531 return raw_parsetree_list;
535 * Given a raw parsetree (gram.y output), and optionally information about
536 * types of parameter symbols ($n), perform parse analysis and rule rewriting.
538 * A list of Query nodes is returned, since either the analyzer or the
539 * rewriter might expand one query to several.
541 * NOTE: for reasons mentioned above, this must be separate from raw parsing.
544 pg_analyze_and_rewrite(Node *parsetree, Oid *paramTypes, int numParams)
546 List *querytree_list;
549 * (1) Perform parse analysis.
551 if (log_parser_stats)
554 querytree_list = parse_analyze(parsetree, paramTypes, numParams);
556 if (log_parser_stats)
557 ShowUsage("PARSE ANALYSIS STATISTICS");
560 * (2) Rewrite the queries, as necessary
562 querytree_list = pg_rewrite_queries(querytree_list);
564 return querytree_list;
568 * Perform rewriting of a list of queries produced by parse analysis.
571 pg_rewrite_queries(List *querytree_list)
573 List *new_list = NIL;
576 if (log_parser_stats)
580 * rewritten queries are collected in new_list. Note there may be
581 * more or fewer than in the original list.
583 foreach(list_item, querytree_list)
585 Query *querytree = (Query *) lfirst(list_item);
587 if (Debug_print_parse)
588 elog_node_display(DEBUG1, "parse tree", querytree,
591 if (querytree->commandType == CMD_UTILITY)
593 /* don't rewrite utilities, just dump 'em into new_list */
594 new_list = lappend(new_list, querytree);
598 /* rewrite regular queries */
599 List *rewritten = QueryRewrite(querytree);
601 new_list = nconc(new_list, rewritten);
605 querytree_list = new_list;
607 if (log_parser_stats)
608 ShowUsage("REWRITER STATISTICS");
610 #ifdef COPY_PARSE_PLAN_TREES
613 * Optional debugging check: pass querytree output through
616 new_list = (List *) copyObject(querytree_list);
617 /* This checks both copyObject() and the equal() routines... */
618 if (!equal(new_list, querytree_list))
619 elog(WARNING, "copyObject() failed to produce an equal parse tree");
621 querytree_list = new_list;
624 if (Debug_print_rewritten)
625 elog_node_display(DEBUG1, "rewritten parse tree", querytree_list,
628 return querytree_list;
632 /* Generate a plan for a single already-rewritten query. */
634 pg_plan_query(Query *querytree)
638 /* Utility commands have no plans. */
639 if (querytree->commandType == CMD_UTILITY)
642 if (log_planner_stats)
645 /* call the optimizer */
646 plan = planner(querytree, false, 0);
648 if (log_planner_stats)
649 ShowUsage("PLANNER STATISTICS");
651 #ifdef COPY_PARSE_PLAN_TREES
652 /* Optional debugging check: pass plan output through copyObject() */
654 Plan *new_plan = (Plan *) copyObject(plan);
657 * equal() currently does not have routines to compare Plan nodes,
658 * so don't try to test equality here. Perhaps fix someday?
661 /* This checks both copyObject() and the equal() routines... */
662 if (!equal(new_plan, plan))
663 elog(WARNING, "copyObject() failed to produce an equal plan tree");
671 * Print plan if debugging.
673 if (Debug_print_plan)
674 elog_node_display(DEBUG1, "plan", plan, Debug_pretty_print);
680 * Generate plans for a list of already-rewritten queries.
682 * If needSnapshot is TRUE, we haven't yet set a snapshot for the current
683 * query. A snapshot must be set before invoking the planner, since it
684 * might try to evaluate user-defined functions. But we must not set a
685 * snapshot if the list contains only utility statements, because some
686 * utility statements depend on not having frozen the snapshot yet.
687 * (We assume that such statements cannot appear together with plannable
688 * statements in the rewriter's output.)
691 pg_plan_queries(List *querytrees, bool needSnapshot)
693 List *plan_list = NIL;
696 foreach(query_list, querytrees)
698 Query *query = (Query *) lfirst(query_list);
701 if (query->commandType == CMD_UTILITY)
703 /* Utility commands have no plans. */
711 needSnapshot = false;
713 plan = pg_plan_query(query);
716 plan_list = lappend(plan_list, plan);
726 * Execute a "simple Query" protocol message.
729 exec_simple_query(const char *query_string)
731 CommandDest dest = whereToSendOutput;
732 MemoryContext oldcontext;
733 List *parsetree_list,
735 struct timeval start_t,
737 bool save_log_duration = log_duration;
738 int save_log_min_duration_statement = log_min_duration_statement;
739 bool save_log_statement_stats = log_statement_stats;
742 * Report query to various monitoring facilities.
744 debug_query_string = query_string;
746 pgstat_report_activity(query_string);
749 * We use save_log_* so "SET log_duration = true" and "SET
750 * log_min_duration_statement = true" don't report incorrect time
751 * because gettimeofday() wasn't called. Similarly,
752 * log_statement_stats has to be captured once.
754 if (save_log_duration || save_log_min_duration_statement != -1)
755 gettimeofday(&start_t, NULL);
757 if (save_log_statement_stats)
761 * Start up a transaction command. All queries generated by the
762 * query_string will be in this same command block, *unless* we find a
763 * BEGIN/COMMIT/ABORT statement; we have to force a new xact command
764 * after one of those, else bad things will happen in xact.c. (Note
765 * that this will normally change current memory context.)
767 start_xact_command();
770 * Zap any pre-existing unnamed statement. (While not strictly
771 * necessary, it seems best to define simple-Query mode as if it used
772 * the unnamed statement and portal; this ensures we recover any
773 * storage used by prior unnamed operations.)
775 unnamed_stmt_pstmt = NULL;
776 if (unnamed_stmt_context)
778 DropDependentPortals(unnamed_stmt_context);
779 MemoryContextDelete(unnamed_stmt_context);
781 unnamed_stmt_context = NULL;
784 * Switch to appropriate context for constructing parsetrees.
786 oldcontext = MemoryContextSwitchTo(MessageContext);
788 QueryContext = CurrentMemoryContext;
791 * Do basic parsing of the query or queries (this should be safe even
792 * if we are in aborted transaction state!)
794 parsetree_list = pg_parse_query(query_string);
797 * Switch back to transaction context to enter the loop.
799 MemoryContextSwitchTo(oldcontext);
802 * Run through the raw parsetree(s) and process each one.
804 foreach(parsetree_item, parsetree_list)
806 Node *parsetree = (Node *) lfirst(parsetree_item);
807 const char *commandTag;
808 char completionTag[COMPLETION_TAG_BUFSIZE];
809 List *querytree_list,
812 DestReceiver *receiver;
816 * Get the command name for use in status display (it also becomes
817 * the default completion tag, down inside PortalRun). Set
818 * ps_status and do any special start-of-SQL-command processing
819 * needed by the destination.
821 commandTag = CreateCommandTag(parsetree);
823 set_ps_display(commandTag);
825 BeginCommand(commandTag, dest);
828 * If we are in an aborted transaction, reject all commands except
829 * COMMIT/ABORT. It is important that this test occur before we
830 * try to do parse analysis, rewrite, or planning, since all those
831 * phases try to do database accesses, which may fail in abort
832 * state. (It might be safe to allow some additional utility
833 * commands in this state, but not many...)
835 if (IsAbortedTransactionBlockState())
837 bool allowit = false;
839 if (IsA(parsetree, TransactionStmt))
841 TransactionStmt *stmt = (TransactionStmt *) parsetree;
843 if (stmt->kind == TRANS_STMT_COMMIT ||
844 stmt->kind == TRANS_STMT_ROLLBACK)
850 (errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
851 errmsg("current transaction is aborted, "
852 "commands ignored until end of transaction block")));
855 /* Make sure we are in a transaction command */
856 start_xact_command();
858 /* If we got a cancel signal in parsing or prior command, quit */
859 CHECK_FOR_INTERRUPTS();
862 * OK to analyze, rewrite, and plan this query.
864 * Switch to appropriate context for constructing querytrees (again,
865 * these must outlive the execution context).
867 oldcontext = MemoryContextSwitchTo(MessageContext);
869 querytree_list = pg_analyze_and_rewrite(parsetree, NULL, 0);
871 plantree_list = pg_plan_queries(querytree_list, true);
873 /* If we got a cancel signal in analysis or planning, quit */
874 CHECK_FOR_INTERRUPTS();
877 * Create unnamed portal to run the query or queries in. If there
878 * already is one, silently drop it.
880 portal = CreatePortal("", true, true);
882 PortalDefineQuery(portal,
890 * Start the portal. No parameters here.
892 PortalStart(portal, NULL);
895 * Select the appropriate output format: text unless we are doing
896 * a FETCH from a binary cursor. (Pretty grotty to have to do
897 * this here --- but it avoids grottiness in other places. Ah,
898 * the joys of backward compatibility...)
900 format = 0; /* TEXT is default */
901 if (IsA(parsetree, FetchStmt))
903 FetchStmt *stmt = (FetchStmt *) parsetree;
907 Portal fportal = GetPortalByName(stmt->portalname);
909 if (PortalIsValid(fportal) &&
910 (fportal->cursorOptions & CURSOR_OPT_BINARY))
911 format = 1; /* BINARY */
914 PortalSetResultFormat(portal, 1, &format);
917 * Now we can create the destination receiver object.
919 receiver = CreateDestReceiver(dest, portal);
922 * Switch back to transaction context for execution.
924 MemoryContextSwitchTo(oldcontext);
927 * Run the portal to completion, and then drop it (and the
930 (void) PortalRun(portal,
936 (*receiver->rDestroy) (receiver);
938 PortalDrop(portal, false);
940 if (IsA(parsetree, TransactionStmt))
943 * If this was a transaction control statement, commit it. We
944 * will start a new xact command for the next command (if
947 finish_xact_command();
949 else if (lnext(parsetree_item) == NIL)
952 * If this is the last parsetree of the query string, close
953 * down transaction statement before reporting
954 * command-complete. This is so that any end-of-transaction
955 * errors are reported before the command-complete message is
956 * issued, to avoid confusing clients who will expect either a
957 * command-complete message or an error, not one and then the
958 * other. But for compatibility with historical Postgres
959 * behavior, we do not force a transaction boundary between
960 * queries appearing in a single query string.
962 finish_xact_command();
967 * We need a CommandCounterIncrement after every query, except
968 * those that start or end a transaction block.
970 CommandCounterIncrement();
974 * Tell client that we're done with this query. Note we emit
975 * exactly one EndCommand report for each raw parsetree, thus one
976 * for each SQL command the client sent, regardless of rewriting.
977 * (But a command aborted by error will not send an EndCommand
980 EndCommand(completionTag, dest);
981 } /* end loop over parsetrees */
984 * Close down transaction statement, if one is open.
986 finish_xact_command();
989 * If there were no parsetrees, return EmptyQueryResponse message.
997 * Combine processing here as we need to calculate the query duration
1000 if (save_log_duration || save_log_min_duration_statement != -1)
1004 gettimeofday(&stop_t, NULL);
1005 if (stop_t.tv_usec < start_t.tv_usec)
1008 stop_t.tv_usec += 1000000;
1010 usecs = (long) (stop_t.tv_sec - start_t.tv_sec) * 1000000 + (long) (stop_t.tv_usec - start_t.tv_usec);
1012 if (save_log_duration)
1014 (errmsg("duration: %ld.%03ld ms",
1015 (long) ((stop_t.tv_sec - start_t.tv_sec) * 1000 +
1016 (stop_t.tv_usec - start_t.tv_usec) / 1000),
1017 (long) (stop_t.tv_usec - start_t.tv_usec) % 1000)));
1020 * Output a duration_statement to the log if the query has exceeded
1021 * the min duration, or if we are to print all durations.
1023 if (save_log_min_duration_statement == 0 ||
1024 (save_log_min_duration_statement > 0 &&
1025 usecs >= save_log_min_duration_statement * 1000))
1027 (errmsg("duration: %ld.%03ld ms statement: %s",
1028 (long) ((stop_t.tv_sec - start_t.tv_sec) * 1000 +
1029 (stop_t.tv_usec - start_t.tv_usec) / 1000),
1030 (long) (stop_t.tv_usec - start_t.tv_usec) % 1000,
1034 if (save_log_statement_stats)
1035 ShowUsage("QUERY STATISTICS");
1037 debug_query_string = NULL;
1041 * exec_parse_message
1043 * Execute a "Parse" protocol message.
1046 exec_parse_message(const char *query_string, /* string to execute */
1047 const char *stmt_name, /* name for prepared stmt */
1048 Oid *paramTypes, /* parameter types */
1049 int numParams) /* number of parameters */
1051 MemoryContext oldcontext;
1052 List *parsetree_list;
1053 const char *commandTag;
1054 List *querytree_list,
1058 bool save_log_statement_stats = log_statement_stats;
1061 * Report query to various monitoring facilities.
1063 debug_query_string = query_string;
1065 pgstat_report_activity(query_string);
1067 set_ps_display("PARSE");
1069 if (save_log_statement_stats)
1073 * Start up a transaction command so we can run parse analysis etc.
1074 * (Note that this will normally change current memory context.)
1075 * Nothing happens if we are already in one.
1077 start_xact_command();
1080 * Switch to appropriate context for constructing parsetrees.
1082 * We have two strategies depending on whether the prepared statement is
1083 * named or not. For a named prepared statement, we do parsing in
1084 * MessageContext and copy the finished trees into the prepared
1085 * statement's private context; then the reset of MessageContext
1086 * releases temporary space used by parsing and planning. For an
1087 * unnamed prepared statement, we assume the statement isn't going to
1088 * hang around long, so getting rid of temp space quickly is probably
1089 * not worth the costs of copying parse/plan trees. So in this case,
1090 * we set up a special context for the unnamed statement, and do all
1091 * the parsing/planning therein.
1093 is_named = (stmt_name[0] != '\0');
1096 /* Named prepared statement --- parse in MessageContext */
1097 oldcontext = MemoryContextSwitchTo(MessageContext);
1101 /* Unnamed prepared statement --- release any prior unnamed stmt */
1102 unnamed_stmt_pstmt = NULL;
1103 if (unnamed_stmt_context)
1105 DropDependentPortals(unnamed_stmt_context);
1106 MemoryContextDelete(unnamed_stmt_context);
1108 unnamed_stmt_context = NULL;
1109 /* create context for parsing/planning */
1110 unnamed_stmt_context =
1111 AllocSetContextCreate(TopMemoryContext,
1112 "unnamed prepared statement",
1113 ALLOCSET_DEFAULT_MINSIZE,
1114 ALLOCSET_DEFAULT_INITSIZE,
1115 ALLOCSET_DEFAULT_MAXSIZE);
1116 oldcontext = MemoryContextSwitchTo(unnamed_stmt_context);
1119 QueryContext = CurrentMemoryContext;
1122 * Do basic parsing of the query or queries (this should be safe even
1123 * if we are in aborted transaction state!)
1125 parsetree_list = pg_parse_query(query_string);
1128 * We only allow a single user statement in a prepared statement. This
1129 * is mainly to keep the protocol simple --- otherwise we'd need to
1130 * worry about multiple result tupdescs and things like that.
1132 if (length(parsetree_list) > 1)
1134 (errcode(ERRCODE_SYNTAX_ERROR),
1135 errmsg("cannot insert multiple commands into a prepared statement")));
1137 if (parsetree_list != NIL)
1139 Node *parsetree = (Node *) lfirst(parsetree_list);
1143 * Get the command name for possible use in status display.
1145 commandTag = CreateCommandTag(parsetree);
1148 * If we are in an aborted transaction, reject all commands except
1149 * COMMIT/ROLLBACK. It is important that this test occur before
1150 * we try to do parse analysis, rewrite, or planning, since all
1151 * those phases try to do database accesses, which may fail in
1152 * abort state. (It might be safe to allow some additional utility
1153 * commands in this state, but not many...)
1155 if (IsAbortedTransactionBlockState())
1157 bool allowit = false;
1159 if (IsA(parsetree, TransactionStmt))
1161 TransactionStmt *stmt = (TransactionStmt *) parsetree;
1163 if (stmt->kind == TRANS_STMT_COMMIT ||
1164 stmt->kind == TRANS_STMT_ROLLBACK)
1170 (errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
1171 errmsg("current transaction is aborted, "
1172 "commands ignored until end of transaction block")));
1176 * OK to analyze, rewrite, and plan this query. Note that the
1177 * originally specified parameter set is not required to be
1178 * complete, so we have to use parse_analyze_varparams().
1180 if (log_parser_stats)
1183 querytree_list = parse_analyze_varparams(parsetree,
1188 * Check all parameter types got determined, and convert array
1189 * representation to a list for storage.
1192 for (i = 0; i < numParams; i++)
1194 Oid ptype = paramTypes[i];
1196 if (ptype == InvalidOid || ptype == UNKNOWNOID)
1198 (errcode(ERRCODE_INDETERMINATE_DATATYPE),
1199 errmsg("could not determine data type of parameter $%d",
1201 param_list = lappendo(param_list, ptype);
1204 if (log_parser_stats)
1205 ShowUsage("PARSE ANALYSIS STATISTICS");
1207 querytree_list = pg_rewrite_queries(querytree_list);
1209 plantree_list = pg_plan_queries(querytree_list, true);
1213 /* Empty input string. This is legal. */
1215 querytree_list = NIL;
1216 plantree_list = NIL;
1220 /* If we got a cancel signal in analysis or planning, quit */
1221 CHECK_FOR_INTERRUPTS();
1224 * Store the query as a prepared statement. See above comments.
1228 StorePreparedStatement(stmt_name,
1237 PreparedStatement *pstmt;
1239 pstmt = (PreparedStatement *) palloc0(sizeof(PreparedStatement));
1240 /* query_string needs to be copied into unnamed_stmt_context */
1241 pstmt->query_string = pstrdup(query_string);
1242 /* the rest is there already */
1243 pstmt->commandTag = commandTag;
1244 pstmt->query_list = querytree_list;
1245 pstmt->plan_list = plantree_list;
1246 pstmt->argtype_list = param_list;
1247 pstmt->context = unnamed_stmt_context;
1248 /* Now the unnamed statement is complete and valid */
1249 unnamed_stmt_pstmt = pstmt;
1252 MemoryContextSwitchTo(oldcontext);
1254 QueryContext = NULL;
1257 * We do NOT close the open transaction command here; that only
1258 * happens when the client sends Sync. Instead, do
1259 * CommandCounterIncrement just in case something happened during
1262 CommandCounterIncrement();
1265 * Send ParseComplete.
1267 if (whereToSendOutput == Remote)
1268 pq_putemptymessage('1');
1270 if (save_log_statement_stats)
1271 ShowUsage("PARSE MESSAGE STATISTICS");
1273 debug_query_string = NULL;
1279 * Process a "Bind" message to create a portal from a prepared statement
1282 exec_bind_message(StringInfo input_message)
1284 const char *portal_name;
1285 const char *stmt_name;
1287 int16 *pformats = NULL;
1290 int16 *rformats = NULL;
1292 PreparedStatement *pstmt;
1294 ParamListInfo params;
1296 pgstat_report_activity("<BIND>");
1298 set_ps_display("BIND");
1301 * Start up a transaction command so we can call functions etc. (Note
1302 * that this will normally change current memory context.) Nothing
1303 * happens if we are already in one.
1305 start_xact_command();
1307 /* Switch back to message context */
1308 MemoryContextSwitchTo(MessageContext);
1310 /* Get the fixed part of the message */
1311 portal_name = pq_getmsgstring(input_message);
1312 stmt_name = pq_getmsgstring(input_message);
1314 /* Get the parameter format codes */
1315 numPFormats = pq_getmsgint(input_message, 2);
1316 if (numPFormats > 0)
1318 pformats = (int16 *) palloc(numPFormats * sizeof(int16));
1319 for (i = 0; i < numPFormats; i++)
1320 pformats[i] = pq_getmsgint(input_message, 2);
1323 /* Get the parameter value count */
1324 numParams = pq_getmsgint(input_message, 2);
1326 if (numPFormats > 1 && numPFormats != numParams)
1328 (errcode(ERRCODE_PROTOCOL_VIOLATION),
1329 errmsg("bind message has %d parameter formats but %d parameters",
1330 numPFormats, numParams)));
1332 /* Find prepared statement */
1333 if (stmt_name[0] != '\0')
1334 pstmt = FetchPreparedStatement(stmt_name, true);
1337 /* special-case the unnamed statement */
1338 pstmt = unnamed_stmt_pstmt;
1341 (errcode(ERRCODE_UNDEFINED_PSTATEMENT),
1342 errmsg("unnamed prepared statement does not exist")));
1345 if (numParams != length(pstmt->argtype_list))
1347 (errcode(ERRCODE_PROTOCOL_VIOLATION),
1348 errmsg("bind message supplies %d parameters, but prepared statement \"%s\" requires %d",
1349 numParams, stmt_name, length(pstmt->argtype_list))));
1352 * Create the portal. Allow silent replacement of an existing portal
1353 * only if the unnamed portal is specified.
1355 if (portal_name[0] == '\0')
1356 portal = CreatePortal(portal_name, true, true);
1358 portal = CreatePortal(portal_name, false, false);
1360 PortalDefineQuery(portal,
1361 pstmt->query_string,
1368 * Fetch parameters, if any, and store in the portal's memory context.
1370 * In an aborted transaction, we can't risk calling user-defined
1371 * functions, but we can't fail to Bind either, so bind all parameters
1376 bool isaborted = IsAbortedTransactionBlockState();
1378 MemoryContext oldContext;
1380 oldContext = MemoryContextSwitchTo(PortalGetHeapMemory(portal));
1382 params = (ParamListInfo)
1383 palloc0((numParams + 1) * sizeof(ParamListInfoData));
1386 foreach(l, pstmt->argtype_list)
1388 Oid ptype = lfirsto(l);
1392 plength = pq_getmsgint(input_message, 4);
1393 isNull = (plength == -1);
1397 const char *pvalue = pq_getmsgbytes(input_message, plength);
1401 /* We don't bother to check the format in this case */
1407 StringInfoData pbuf;
1410 if (numPFormats > 1)
1411 pformat = pformats[i];
1412 else if (numPFormats > 0)
1413 pformat = pformats[0];
1415 pformat = 0; /* default = text */
1418 * Rather than copying data around, we just set up a
1419 * phony StringInfo pointing to the correct portion of
1420 * the message buffer. We assume we can scribble on
1421 * the message buffer so as to maintain the convention
1422 * that StringInfos have a trailing null. This is
1423 * grotty but is a big win when dealing with very
1424 * large parameter strings.
1426 pbuf.data = (char *) pvalue;
1427 pbuf.maxlen = plength + 1;
1431 csave = pbuf.data[plength];
1432 pbuf.data[plength] = '\0';
1440 getTypeInputInfo(ptype, &typInput, &typElem);
1443 * We have to do encoding conversion before
1444 * calling the typinput routine.
1447 pg_client_to_server((unsigned char *) pbuf.data,
1450 OidFunctionCall3(typInput,
1451 CStringGetDatum(pstring),
1452 ObjectIdGetDatum(typElem),
1454 /* Free result of encoding conversion, if any */
1455 if (pstring != pbuf.data)
1458 else if (pformat == 1)
1464 * Call the parameter type's binary input
1467 getTypeBinaryInputInfo(ptype, &typReceive, &typElem);
1470 OidFunctionCall2(typReceive,
1471 PointerGetDatum(&pbuf),
1472 ObjectIdGetDatum(typElem));
1474 /* Trouble if it didn't eat the whole buffer */
1475 if (pbuf.cursor != pbuf.len)
1477 (errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
1478 errmsg("incorrect binary data format in bind parameter %d",
1484 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
1485 errmsg("unsupported format code: %d",
1489 /* Restore message buffer contents */
1490 pbuf.data[plength] = csave;
1494 params[i].kind = PARAM_NUM;
1495 params[i].id = i + 1;
1496 params[i].isnull = isNull;
1501 params[i].kind = PARAM_INVALID;
1503 MemoryContextSwitchTo(oldContext);
1508 /* Get the result format codes */
1509 numRFormats = pq_getmsgint(input_message, 2);
1510 if (numRFormats > 0)
1512 rformats = (int16 *) palloc(numRFormats * sizeof(int16));
1513 for (i = 0; i < numRFormats; i++)
1514 rformats[i] = pq_getmsgint(input_message, 2);
1517 pq_getmsgend(input_message);
1520 * Start portal execution.
1522 PortalStart(portal, params);
1525 * Apply the result format requests to the portal.
1527 PortalSetResultFormat(portal, numRFormats, rformats);
1530 * Send BindComplete.
1532 if (whereToSendOutput == Remote)
1533 pq_putemptymessage('2');
1537 * exec_execute_message
1539 * Process an "Execute" message for a portal
1542 exec_execute_message(const char *portal_name, long max_rows)
1545 DestReceiver *receiver;
1547 bool is_trans_stmt = false;
1548 bool is_trans_exit = false;
1550 char completionTag[COMPLETION_TAG_BUFSIZE];
1552 /* Adjust destination to tell printtup.c what to do */
1553 dest = whereToSendOutput;
1555 dest = RemoteExecute;
1557 portal = GetPortalByName(portal_name);
1558 if (!PortalIsValid(portal))
1560 (errcode(ERRCODE_UNDEFINED_CURSOR),
1561 errmsg("portal \"%s\" does not exist", portal_name)));
1564 * If the original query was a null string, just return
1565 * EmptyQueryResponse.
1567 if (portal->commandTag == NULL)
1569 Assert(portal->parseTrees == NIL);
1574 if (portal->sourceText)
1576 debug_query_string = portal->sourceText;
1577 pgstat_report_activity(portal->sourceText);
1581 debug_query_string = "execute message";
1582 pgstat_report_activity("<EXECUTE>");
1585 set_ps_display(portal->commandTag);
1587 BeginCommand(portal->commandTag, dest);
1589 /* Check for transaction-control commands */
1590 if (length(portal->parseTrees) == 1)
1592 Query *query = (Query *) lfirst(portal->parseTrees);
1594 if (query->commandType == CMD_UTILITY &&
1595 query->utilityStmt != NULL &&
1596 IsA(query->utilityStmt, TransactionStmt))
1598 TransactionStmt *stmt = (TransactionStmt *) query->utilityStmt;
1600 is_trans_stmt = true;
1601 if (stmt->kind == TRANS_STMT_COMMIT ||
1602 stmt->kind == TRANS_STMT_ROLLBACK)
1603 is_trans_exit = true;
1608 * Create dest receiver in MessageContext (we don't want it in
1609 * transaction context, because that may get deleted if portal
1612 receiver = CreateDestReceiver(dest, portal);
1615 * Ensure we are in a transaction command (this should normally be the
1616 * case already due to prior BIND).
1618 start_xact_command();
1621 * If we are in aborted transaction state, the only portals we can
1622 * actually run are those containing COMMIT or ROLLBACK commands.
1624 if (IsAbortedTransactionBlockState())
1628 (errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
1629 errmsg("current transaction is aborted, "
1630 "commands ignored until end of transaction block")));
1633 /* Check for cancel signal before we start execution */
1634 CHECK_FOR_INTERRUPTS();
1637 * Okay to run the portal.
1640 max_rows = FETCH_ALL;
1642 completed = PortalRun(portal,
1648 (*receiver->rDestroy) (receiver);
1655 * If this was a transaction control statement, commit it. We
1656 * will start a new xact command for the next command (if
1659 finish_xact_command();
1664 * We need a CommandCounterIncrement after every query, except
1665 * those that start or end a transaction block.
1667 CommandCounterIncrement();
1670 /* Send appropriate CommandComplete to client */
1671 EndCommand(completionTag, dest);
1675 /* Portal run not complete, so send PortalSuspended */
1676 if (whereToSendOutput == Remote)
1677 pq_putemptymessage('s');
1680 debug_query_string = NULL;
1684 * exec_describe_statement_message
1686 * Process a "Describe" message for a prepared statement
1689 exec_describe_statement_message(const char *stmt_name)
1691 PreparedStatement *pstmt;
1696 /* Find prepared statement */
1697 if (stmt_name[0] != '\0')
1698 pstmt = FetchPreparedStatement(stmt_name, true);
1701 /* special-case the unnamed statement */
1702 pstmt = unnamed_stmt_pstmt;
1705 (errcode(ERRCODE_UNDEFINED_PSTATEMENT),
1706 errmsg("unnamed prepared statement does not exist")));
1709 if (whereToSendOutput != Remote)
1710 return; /* can't actually do anything... */
1713 * First describe the parameters...
1715 pq_beginmessage(&buf, 't'); /* parameter description message type */
1716 pq_sendint(&buf, length(pstmt->argtype_list), 2);
1718 foreach(l, pstmt->argtype_list)
1720 Oid ptype = lfirsto(l);
1722 pq_sendint(&buf, (int) ptype, 4);
1724 pq_endmessage(&buf);
1727 * Next send RowDescription or NoData to describe the result...
1729 tupdesc = FetchPreparedStatementResultDesc(pstmt);
1734 if (ChoosePortalStrategy(pstmt->query_list) == PORTAL_ONE_SELECT)
1735 targetlist = ((Query *) lfirst(pstmt->query_list))->targetList;
1738 SendRowDescriptionMessage(tupdesc, targetlist, NULL);
1741 pq_putemptymessage('n'); /* NoData */
1746 * exec_describe_portal_message
1748 * Process a "Describe" message for a portal
1751 exec_describe_portal_message(const char *portal_name)
1755 portal = GetPortalByName(portal_name);
1756 if (!PortalIsValid(portal))
1758 (errcode(ERRCODE_UNDEFINED_CURSOR),
1759 errmsg("portal \"%s\" does not exist", portal_name)));
1761 if (whereToSendOutput != Remote)
1762 return; /* can't actually do anything... */
1764 if (portal->tupDesc)
1768 if (portal->strategy == PORTAL_ONE_SELECT)
1769 targetlist = ((Query *) lfirst(portal->parseTrees))->targetList;
1772 SendRowDescriptionMessage(portal->tupDesc, targetlist,
1776 pq_putemptymessage('n'); /* NoData */
1781 * Convenience routines for starting/committing a single command.
1784 start_xact_command(void)
1789 (errmsg_internal("StartTransactionCommand")));
1790 StartTransactionCommand();
1792 /* Set statement timeout running, if any */
1793 if (StatementTimeout > 0)
1794 enable_sig_alarm(StatementTimeout, true);
1796 xact_started = true;
1801 finish_xact_command(void)
1805 /* Invoke IMMEDIATE constraint triggers */
1806 DeferredTriggerEndQuery();
1808 /* Cancel any active statement timeout before committing */
1809 disable_sig_alarm(true);
1811 /* Now commit the command */
1813 (errmsg_internal("CommitTransactionCommand")));
1815 CommitTransactionCommand();
1817 #ifdef MEMORY_CONTEXT_CHECKING
1818 /* Check all memory contexts that weren't freed during commit */
1819 /* (those that were, were checked before being deleted) */
1820 MemoryContextCheck(TopMemoryContext);
1823 #ifdef SHOW_MEMORY_STATS
1824 /* Print mem stats after each commit for leak tracking */
1826 MemoryContextStats(TopMemoryContext);
1829 xact_started = false;
1834 /* --------------------------------
1835 * signal handler routines used in PostgresMain()
1836 * --------------------------------
1840 * quickdie() occurs when signalled SIGQUIT by the postmaster.
1842 * Some backend has bought the farm,
1843 * so we need to stop what we're doing and exit.
1846 quickdie(SIGNAL_ARGS)
1848 PG_SETMASK(&BlockSig);
1851 * Ideally this should be ereport(FATAL), but then we'd not get
1852 * control back (perhaps could fix by doing local sigsetjmp?)
1855 (errcode(ERRCODE_CRASH_SHUTDOWN),
1856 errmsg("terminating connection because of crash of another server process"),
1857 errdetail("The postmaster has commanded this server process to roll back"
1858 " the current transaction and exit, because another"
1859 " server process exited abnormally and possibly corrupted"
1861 errhint("In a moment you should be able to reconnect to the"
1862 " database and repeat your command.")));
1865 * DO NOT proc_exit() -- we're here because shared memory may be
1866 * corrupted, so we don't want to try to clean up our transaction.
1867 * Just nail the windows shut and get out of town.
1869 * Note we do exit(1) not exit(0). This is to force the postmaster into
1870 * a system reset cycle if some idiot DBA sends a manual SIGQUIT to a
1871 * random backend. This is necessary precisely because we don't clean
1872 * up our shared memory state.
1878 * Shutdown signal from postmaster: abort transaction and exit
1879 * at soonest convenient time
1884 int save_errno = errno;
1886 /* Don't joggle the elbow of proc_exit */
1887 if (!proc_exit_inprogress)
1889 InterruptPending = true;
1890 ProcDiePending = true;
1893 * If it's safe to interrupt, and we're waiting for input or a
1894 * lock, service the interrupt immediately
1896 if (ImmediateInterruptOK && InterruptHoldoffCount == 0 &&
1897 CritSectionCount == 0)
1899 /* bump holdoff count to make ProcessInterrupts() a no-op */
1900 /* until we are done getting ready for it */
1901 InterruptHoldoffCount++;
1902 DisableNotifyInterrupt();
1903 /* Make sure CheckDeadLock won't run while shutting down... */
1905 InterruptHoldoffCount--;
1906 ProcessInterrupts();
1914 * Timeout or shutdown signal from postmaster during client authentication.
1917 * XXX: possible future improvement: try to send a message indicating
1918 * why we are disconnecting. Problem is to be sure we don't block while
1919 * doing so, nor mess up the authentication message exchange.
1922 authdie(SIGNAL_ARGS)
1928 * Query-cancel signal from postmaster: abort current transaction
1929 * at soonest convenient time
1932 StatementCancelHandler(SIGNAL_ARGS)
1934 int save_errno = errno;
1937 * Don't joggle the elbow of proc_exit, nor an already-in-progress
1940 if (!proc_exit_inprogress && !InError)
1942 InterruptPending = true;
1943 QueryCancelPending = true;
1946 * If it's safe to interrupt, and we're waiting for a lock,
1947 * service the interrupt immediately. No point in interrupting if
1948 * we're waiting for input, however.
1950 if (ImmediateInterruptOK && InterruptHoldoffCount == 0 &&
1951 CritSectionCount == 0)
1953 /* bump holdoff count to make ProcessInterrupts() a no-op */
1954 /* until we are done getting ready for it */
1955 InterruptHoldoffCount++;
1956 if (LockWaitCancel())
1958 DisableNotifyInterrupt();
1959 InterruptHoldoffCount--;
1960 ProcessInterrupts();
1963 InterruptHoldoffCount--;
1970 /* signal handler for floating point exception */
1972 FloatExceptionHandler(SIGNAL_ARGS)
1975 (errcode(ERRCODE_FLOATING_POINT_EXCEPTION),
1976 errmsg("floating-point exception"),
1977 errdetail("An invalid floating-point operation was signaled. "
1978 "This probably means an out-of-range result or an "
1979 "invalid operation, such as division by zero.")));
1982 /* SIGHUP: set flag to re-read config file at next convenient time */
1984 SigHupHandler(SIGNAL_ARGS)
1991 * ProcessInterrupts: out-of-line portion of CHECK_FOR_INTERRUPTS() macro
1993 * If an interrupt condition is pending, and it's safe to service it,
1994 * then clear the flag and accept the interrupt. Called only when
1995 * InterruptPending is true.
1998 ProcessInterrupts(void)
2000 /* OK to accept interrupt now? */
2001 if (InterruptHoldoffCount != 0 || CritSectionCount != 0)
2003 InterruptPending = false;
2006 ProcDiePending = false;
2007 QueryCancelPending = false; /* ProcDie trumps QueryCancel */
2008 ImmediateInterruptOK = false; /* not idle anymore */
2009 DisableNotifyInterrupt();
2011 (errcode(ERRCODE_ADMIN_SHUTDOWN),
2012 errmsg("terminating connection due to administrator command")));
2014 if (QueryCancelPending)
2016 QueryCancelPending = false;
2017 ImmediateInterruptOK = false; /* not idle anymore */
2018 DisableNotifyInterrupt();
2020 (errcode(ERRCODE_QUERY_CANCELED),
2021 errmsg("canceling query due to user request")));
2023 /* If we get here, do nothing (probably, QueryCancelPending was reset) */
2028 * check_stack_depth: check for excessively deep recursion
2030 * This should be called someplace in any recursive routine that might possibly
2031 * recurse deep enough to overflow the stack. Most Unixen treat stack
2032 * overflow as an unrecoverable SIGSEGV, so we want to error out ourselves
2033 * before hitting the hardware limit. Unfortunately we have no direct way
2034 * to detect the hardware limit, so we have to rely on the admin to set a
2035 * GUC variable for it ...
2038 check_stack_depth(void)
2044 * Compute distance from PostgresMain's local variables to my own
2046 * Note: in theory stack_depth should be ptrdiff_t or some such, but
2047 * since the whole point of this code is to bound the value to something
2048 * much less than integer-sized, int should work fine.
2050 stack_depth = (int) (stack_base_ptr - &stack_top_loc);
2052 * Take abs value, since stacks grow up on some machines, down on others
2054 if (stack_depth < 0)
2055 stack_depth = -stack_depth;
2059 * The test on stack_base_ptr prevents us from erroring out if called
2060 * during process setup or in a non-backend process. Logically it should
2061 * be done first, but putting it here avoids wasting cycles during normal
2064 if (stack_depth > max_stack_depth_bytes &&
2065 stack_base_ptr != NULL)
2068 (errcode(ERRCODE_STATEMENT_TOO_COMPLEX),
2069 errmsg("stack depth limit exceeded"),
2070 errhint("Increase the configuration parameter \"max_stack_depth\".")));
2074 /* GUC assign hook to update max_stack_depth_bytes from max_stack_depth */
2076 assign_max_stack_depth(int newval, bool doit, GucSource source)
2078 /* Range check was already handled by guc.c */
2080 max_stack_depth_bytes = newval * 1024;
2086 usage(const char *progname)
2088 printf(gettext("%s is the PostgreSQL stand-alone backend. It is not\nintended to be used by normal users.\n\n"), progname);
2090 printf(gettext("Usage:\n %s [OPTION]... [DBNAME]\n\n"), progname);
2091 printf(gettext("Options:\n"));
2092 #ifdef USE_ASSERT_CHECKING
2093 printf(gettext(" -A 1|0 enable/disable run-time assert checking\n"));
2095 printf(gettext(" -B NBUFFERS number of shared buffers\n"));
2096 printf(gettext(" -c NAME=VALUE set run-time parameter\n"));
2097 printf(gettext(" -d 0-5 debugging level (0 is off)\n"));
2098 printf(gettext(" -D DATADIR database directory\n"));
2099 printf(gettext(" -e use European date input format (DMY)\n"));
2100 printf(gettext(" -E echo query before execution\n"));
2101 printf(gettext(" -F turn fsync off\n"));
2102 printf(gettext(" -N do not use newline as interactive query delimiter\n"));
2103 printf(gettext(" -o FILENAME send stdout and stderr to given file\n"));
2104 printf(gettext(" -P disable system indexes\n"));
2105 printf(gettext(" -s show statistics after each query\n"));
2106 printf(gettext(" -S WORK-MEM set amount of memory for sorts (in kbytes)\n"));
2107 printf(gettext(" --describe-config describe configuration parameters, then exit\n"));
2108 printf(gettext(" --help show this help, then exit\n"));
2109 printf(gettext(" --version output version information, then exit\n"));
2110 printf(gettext("\nDeveloper options:\n"));
2111 printf(gettext(" -f s|i|n|m|h forbid use of some plan types\n"));
2112 printf(gettext(" -i do not execute queries\n"));
2113 printf(gettext(" -O allow system table structure changes\n"));
2114 printf(gettext(" -t pa|pl|ex show timings after each query\n"));
2115 printf(gettext(" -W NUM wait NUM seconds to allow attach from a debugger\n"));
2116 printf(gettext("\nReport bugs to <pgsql-bugs@postgresql.org>.\n"));
2121 /* ----------------------------------------------------------------
2123 * postgres main loop -- all backends, interactive or otherwise start here
2125 * argc/argv are the command line arguments to be used. (When being forked
2126 * by the postmaster, these are not the original argv array of the process.)
2127 * username is the (possibly authenticated) PostgreSQL user name to be used
2129 * ----------------------------------------------------------------
2132 PostgresMain(int argc, char *argv[], const char *username)
2135 const char *dbname = NULL;
2136 char *potential_DataDir = NULL;
2142 GucSource gucsource;
2146 StringInfoData input_message;
2147 volatile bool send_rfq = true;
2150 * Catch standard options before doing much else. This even works on
2151 * systems without getopt_long.
2153 if (!IsUnderPostmaster && argc > 1)
2155 if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
2160 if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
2162 puts(PG_VERSIONSTR);
2168 * initialize globals (already done if under postmaster, but not if
2169 * standalone; cheap enough to do over)
2171 MyProcPid = getpid();
2174 * Fire up essential subsystems: error and memory management
2176 * If we are running under the postmaster, this is done already.
2178 if (!IsUnderPostmaster)
2179 MemoryContextInit();
2181 set_ps_display("startup");
2183 SetProcessingMode(InitProcessing);
2185 /* Set up reference point for stack depth checking */
2186 stack_base_ptr = &stack_base;
2188 if (my_exec_path[0] == '\0' && find_my_exec(argv[0], my_exec_path) < 0)
2190 gettext("%s: could not locate my own executable path"),
2193 get_pkglib_path(my_exec_path, pkglib_path);
2196 * Set default values for command-line options.
2200 if (!IsUnderPostmaster)
2202 InitializeGUCOptions();
2203 potential_DataDir = getenv("PGDATA");
2207 * parse command line arguments
2209 * There are now two styles of command line layout for the backend:
2211 * For interactive use (not started from postmaster) the format is
2212 * postgres [switches] [databasename]
2213 * If the databasename is omitted it is taken to be the user name.
2215 * When started from the postmaster, the format is
2216 * postgres [secure switches] -p databasename [insecure switches]
2217 * Switches appearing after -p came from the client (via "options"
2218 * field of connection request). For security reasons we restrict
2219 * what these switches can do.
2223 /* all options are allowed until '-p' */
2225 ctx = debug_context = PGC_POSTMASTER;
2226 gucsource = PGC_S_ARGV; /* initial switches came from command line */
2228 while ((flag = getopt(argc, argv, "A:B:c:D:d:Eef:FiNOPo:p:S:st:v:W:-:")) != -1)
2232 #ifdef USE_ASSERT_CHECKING
2233 SetConfigOption("debug_assertions", optarg, ctx, gucsource);
2236 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
2237 errmsg("assert checking is not compiled in")));
2244 * specify the size of buffer pool
2246 SetConfigOption("shared_buffers", optarg, ctx, gucsource);
2249 case 'D': /* PGDATA directory */
2251 potential_DataDir = optarg;
2254 case 'd': /* debug level */
2257 * Client option can't decrease debug level. We have
2258 * to do the test here because we group priv and
2259 * client set GUC calls below, after we know the final
2262 if (ctx != PGC_BACKEND || atoi(optarg) > debug_flag)
2264 debug_flag = atoi(optarg);
2265 debug_context = ctx; /* save context for use
2267 /* Set server debugging level. */
2268 if (debug_flag != 0)
2270 char *debugstr = palloc(strlen("debug") + strlen(optarg) + 1);
2272 sprintf(debugstr, "debug%s", optarg);
2273 SetConfigOption("log_min_messages", debugstr, ctx, gucsource);
2280 * -d0 allows user to prevent postmaster debug
2281 * from propagating to backend. It would be
2282 * nice to set it to the postgresql.conf value
2285 SetConfigOption("log_min_messages", "notice",
2294 * E - echo the query the user entered
2302 * Use European date input format (DMY)
2304 SetConfigOption("datestyle", "euro", ctx, gucsource);
2312 SetConfigOption("fsync", "false", ctx, gucsource);
2318 * f - forbid generation of certain plans
2323 case 's': /* seqscan */
2324 tmp = "enable_seqscan";
2326 case 'i': /* indexscan */
2327 tmp = "enable_indexscan";
2329 case 't': /* tidscan */
2330 tmp = "enable_tidscan";
2332 case 'n': /* nestloop */
2333 tmp = "enable_nestloop";
2335 case 'm': /* mergejoin */
2336 tmp = "enable_mergejoin";
2338 case 'h': /* hashjoin */
2339 tmp = "enable_hashjoin";
2345 SetConfigOption(tmp, "false", ctx, gucsource);
2351 * N - Don't use newline as a query delimiter
2359 * allow system table structure modifications
2361 if (secure) /* XXX safe to allow from client??? */
2362 allowSystemTableMods = true;
2368 * ignore system indexes
2370 * As of PG 7.4 this is safe to allow from the client,
2371 * since it only disables reading the system indexes,
2372 * not writing them. Worst case consequence is slowness.
2374 IgnoreSystemIndexes(true);
2380 * o - send output (stdout and stderr) to the given file
2383 StrNCpy(OutputFileName, optarg, MAXPGPATH);
2388 * p - special flag passed if backend was forked by a
2393 dbname = strdup(optarg);
2395 secure = false; /* subsequent switches are NOT
2398 gucsource = PGC_S_CLIENT;
2405 * S - amount of sort memory to use in 1k bytes
2407 SetConfigOption("work_mem", optarg, ctx, gucsource);
2413 * s - report usage statistics (timings) after each query
2415 SetConfigOption("log_statement_stats", "true", ctx, gucsource);
2420 * tell postgres to report usage statistics (timings) for
2423 * -tpa[rser] = print stats for parser time of each query
2424 * -tpl[anner] = print stats for planner time of each query
2425 * -te[xecutor] = print stats for executor time of each query
2426 * caution: -s can not be used together with -t.
2433 if (optarg[1] == 'a')
2434 tmp = "log_parser_stats";
2435 else if (optarg[1] == 'l')
2436 tmp = "log_planner_stats";
2441 tmp = "log_executor_stats";
2448 SetConfigOption(tmp, "true", ctx, gucsource);
2453 FrontendProtocol = (ProtocolVersion) atoi(optarg);
2459 * wait N seconds to allow attach from a debugger
2461 pg_usleep(atoi(optarg)*1000000L);
2470 ParseLongOption(optarg, &name, &value);
2475 (errcode(ERRCODE_SYNTAX_ERROR),
2476 errmsg("--%s requires a value",
2480 (errcode(ERRCODE_SYNTAX_ERROR),
2481 errmsg("-c %s requires a value",
2485 SetConfigOption(name, value, ctx, gucsource);
2499 * -d is not the same as setting log_min_messages because it enables
2500 * other output options.
2502 if (debug_flag >= 1)
2504 SetConfigOption("log_connections", "true", debug_context, gucsource);
2505 SetConfigOption("log_disconnections", "true", debug_context, gucsource);
2507 if (debug_flag >= 2)
2508 SetConfigOption("log_statement", "all", debug_context, gucsource);
2509 if (debug_flag >= 3)
2510 SetConfigOption("debug_print_parse", "true", debug_context, gucsource);
2511 if (debug_flag >= 4)
2512 SetConfigOption("debug_print_plan", "true", debug_context, gucsource);
2513 if (debug_flag >= 5)
2514 SetConfigOption("debug_print_rewritten", "true", debug_context, gucsource);
2517 * Process any additional GUC variable settings passed in startup
2520 if (MyProcPort != NULL)
2522 List *gucopts = MyProcPort->guc_options;
2529 name = lfirst(gucopts);
2530 gucopts = lnext(gucopts);
2531 value = lfirst(gucopts);
2532 gucopts = lnext(gucopts);
2533 SetConfigOption(name, value, PGC_BACKEND, PGC_S_CLIENT);
2537 * set up handler to log session end.
2539 if (IsUnderPostmaster && Log_disconnections)
2540 on_proc_exit(log_disconnections,0);
2543 if (!IsUnderPostmaster || ExecBackend)
2545 if (!potential_DataDir)
2548 gettext("%s does not know where to find the database system data.\n"
2549 "You must specify the directory that contains the database system\n"
2550 "either by specifying the -D invocation option or by setting the\n"
2551 "PGDATA environment variable.\n"),
2555 SetDataDir(potential_DataDir);
2559 /* Acquire configuration parameters */
2560 if (IsUnderPostmaster)
2563 read_nondefault_variables();
2566 ProcessConfigFile(PGC_POSTMASTER);
2569 * Set up signal handlers and masks.
2571 * Note that postmaster blocked all signals before forking child process,
2572 * so there is no race condition whereby we might receive a signal
2573 * before we have set up the handler.
2575 * Also note: it's best not to use any signals that are SIG_IGNored in
2576 * the postmaster. If such a signal arrives before we are able to
2577 * change the handler to non-SIG_IGN, it'll get dropped. Instead,
2578 * make a dummy handler in the postmaster to reserve the signal. (Of
2579 * course, this isn't an issue for signals that are locally generated,
2580 * such as SIGALRM and SIGPIPE.)
2582 pqsignal(SIGHUP, SigHupHandler); /* set flag to read config file */
2583 pqsignal(SIGINT, StatementCancelHandler); /* cancel current query */
2584 pqsignal(SIGTERM, die); /* cancel current query and exit */
2585 pqsignal(SIGQUIT, quickdie); /* hard crash time */
2586 pqsignal(SIGALRM, handle_sig_alarm); /* timeout conditions */
2589 * Ignore failure to write to frontend. Note: if frontend closes
2590 * connection, we will notice it and exit cleanly when control next
2591 * returns to outer loop. This seems safer than forcing exit in the
2592 * midst of output during who-knows-what operation...
2594 pqsignal(SIGPIPE, SIG_IGN);
2595 pqsignal(SIGUSR1, SIG_IGN); /* this signal available for use */
2597 pqsignal(SIGUSR2, Async_NotifyHandler); /* flush also sinval cache */
2598 pqsignal(SIGFPE, FloatExceptionHandler);
2601 * Reset some signals that are accepted by postmaster but not by
2604 pqsignal(SIGCHLD, SIG_DFL); /* system() requires this on some
2609 /* We allow SIGQUIT (quickdie) at all times */
2610 #ifdef HAVE_SIGPROCMASK
2611 sigdelset(&BlockSig, SIGQUIT);
2613 BlockSig &= ~(sigmask(SIGQUIT));
2616 PG_SETMASK(&BlockSig); /* block everything except SIGQUIT */
2619 if (IsUnderPostmaster)
2621 /* noninteractive case: nothing should be left after switches */
2622 if (errs || argc != optind || dbname == NULL)
2625 (errcode(ERRCODE_SYNTAX_ERROR),
2626 errmsg("invalid command-line arguments for server process"),
2627 errhint("Try \"%s --help\" for more information.", argv[0])));
2636 /* interactive case: database name can be last arg on command line */
2637 if (errs || argc - optind > 1)
2640 (errcode(ERRCODE_SYNTAX_ERROR),
2641 errmsg("%s: invalid command-line arguments",
2643 errhint("Try \"%s --help\" for more information.", argv[0])));
2645 else if (argc - optind == 1)
2646 dbname = argv[optind];
2647 else if ((dbname = username) == NULL)
2650 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
2651 errmsg("%s: no database nor user name specified",
2656 * Validate we have been given a reasonable-looking DataDir (if
2657 * under postmaster, assume postmaster did this already).
2659 ValidatePgVersion(DataDir);
2662 * Create lockfile for data directory.
2664 CreateDataDirLockFile(DataDir, false);
2670 * Start up xlog for standalone backend, and register to have it
2671 * closed down at exit.
2674 on_shmem_exit(ShutdownXLOG, 0);
2677 * Read any existing FSM cache file, and register to write one out
2681 on_shmem_exit(DumpFreeSpaceMap, 0);
2685 * General initialization.
2687 * NOTE: if you are tempted to add code in this vicinity, consider
2688 * putting it inside InitPostgres() instead. In particular, anything
2689 * that involves database access should be there, not here.
2692 (errmsg_internal("InitPostgres")));
2693 InitPostgres(dbname, username);
2695 SetProcessingMode(NormalProcessing);
2698 * Send this backend's cancellation info to the frontend.
2700 if (whereToSendOutput == Remote &&
2701 PG_PROTOCOL_MAJOR(FrontendProtocol) >= 2)
2705 pq_beginmessage(&buf, 'K');
2706 pq_sendint(&buf, (int32) MyProcPid, sizeof(int32));
2707 pq_sendint(&buf, (int32) MyCancelKey, sizeof(int32));
2708 pq_endmessage(&buf);
2709 /* Need not flush since ReadyForQuery will do it. */
2712 /* Welcome banner for standalone case */
2713 if (whereToSendOutput == Debug)
2714 printf("\nPostgreSQL stand-alone backend %s\n", PG_VERSION);
2717 * Create the memory context we will use in the main loop.
2719 * MessageContext is reset once per iteration of the main loop, ie, upon
2720 * completion of processing of each command message from the client.
2722 MessageContext = AllocSetContextCreate(TopMemoryContext,
2724 ALLOCSET_DEFAULT_MINSIZE,
2725 ALLOCSET_DEFAULT_INITSIZE,
2726 ALLOCSET_DEFAULT_MAXSIZE);
2729 * Tell the statistics collector that we're alive and
2730 * to which database we belong.
2736 * POSTGRES main processing loop begins here
2738 * If an exception is encountered, processing resumes here so we abort
2739 * the current transaction and start a new one.
2742 if (sigsetjmp(Warn_restart, 1) != 0)
2745 * NOTE: if you are tempted to add more code in this if-block,
2746 * consider the probability that it should be in
2747 * AbortTransaction() instead.
2749 * Make sure we're not interrupted while cleaning up. Also forget
2750 * any pending QueryCancel request, since we're aborting anyway.
2751 * Force InterruptHoldoffCount to a known state in case we
2752 * ereport'd from inside a holdoff section.
2754 ImmediateInterruptOK = false;
2755 QueryCancelPending = false;
2756 InterruptHoldoffCount = 1;
2757 CritSectionCount = 0; /* should be unnecessary, but... */
2758 disable_sig_alarm(true);
2759 QueryCancelPending = false; /* again in case timeout occurred */
2760 DisableNotifyInterrupt();
2761 debug_query_string = NULL;
2764 * Make sure we are in a valid memory context during recovery.
2766 * We use ErrorContext in hopes that it will have some free space
2767 * even if we're otherwise up against it...
2769 MemoryContextSwitchTo(ErrorContext);
2771 /* Do the recovery */
2773 (errmsg_internal("AbortCurrentTransaction")));
2774 AbortCurrentTransaction();
2777 * Now return to normal top-level context and clear ErrorContext
2780 MemoryContextSwitchTo(TopMemoryContext);
2781 MemoryContextResetAndDeleteChildren(ErrorContext);
2782 ActivePortal = NULL;
2783 PortalContext = NULL;
2784 QueryContext = NULL;
2787 * Clear flag to indicate that we got out of error recovery mode
2788 * successfully. (Flag was set in elog.c before longjmp().)
2791 xact_started = false;
2794 * Clear flag that causes accounting for cost based vacuum.
2796 VacuumCostActive = false;
2799 * If we were handling an extended-query-protocol message,
2800 * initiate skip till next Sync. This also causes us not to issue
2801 * ReadyForQuery (until we get Sync).
2803 if (doing_extended_query_message)
2804 ignore_till_sync = true;
2807 * Exit interrupt holdoff section we implicitly established above.
2809 RESUME_INTERRUPTS();
2812 Warn_restart_ready = true; /* we can now handle ereport(ERROR) */
2814 PG_SETMASK(&UnBlockSig);
2816 if (!ignore_till_sync)
2817 send_rfq = true; /* initially, or after error */
2820 * Non-error queries loop here.
2826 * At top of loop, reset extended-query-message flag, so that any
2827 * errors encountered in "idle" state don't provoke skip.
2829 doing_extended_query_message = false;
2832 * Release storage left over from prior query cycle, and create a
2833 * new query input buffer in the cleared MessageContext.
2835 MemoryContextSwitchTo(MessageContext);
2836 MemoryContextResetAndDeleteChildren(MessageContext);
2838 initStringInfo(&input_message);
2841 * (1) If we've reached idle state, tell the frontend we're ready
2844 * Note: this includes fflush()'ing the last of the prior output.
2846 * This is also a good time to send collected statistics to the
2847 * collector, and to update the PS stats display. We avoid doing
2848 * those every time through the message loop because it'd slow down
2849 * processing of batched messages.
2853 pgstat_report_tabstat();
2855 if (IsTransactionOrTransactionBlock())
2857 set_ps_display("idle in transaction");
2858 pgstat_report_activity("<IDLE> in transaction");
2862 set_ps_display("idle");
2863 pgstat_report_activity("<IDLE>");
2866 ReadyForQuery(whereToSendOutput);
2871 * (2) deal with pending asynchronous NOTIFY from other backends,
2872 * and enable async.c's signal handler to execute NOTIFY directly.
2873 * Then set up other stuff needed before blocking for input.
2875 QueryCancelPending = false; /* forget any earlier CANCEL
2878 EnableNotifyInterrupt();
2880 /* Allow "die" interrupt to be processed while waiting */
2881 ImmediateInterruptOK = true;
2882 /* and don't forget to detect one that already arrived */
2883 QueryCancelPending = false;
2884 CHECK_FOR_INTERRUPTS();
2887 * (3) read a command (loop blocks here)
2890 firstchar = ReadCommand(&input_message);
2895 * (4) disable async signal conditions again.
2897 ImmediateInterruptOK = false;
2898 QueryCancelPending = false; /* forget any CANCEL signal */
2900 DisableNotifyInterrupt();
2903 * (5) check for any other interesting events that happened while
2910 read_nondefault_variables();
2912 ProcessConfigFile(PGC_SIGHUP);
2917 * (6) process the command. But ignore it if we're skipping till
2920 if (ignore_till_sync && firstchar != EOF)
2925 case 'Q': /* simple query */
2927 const char *query_string;
2929 query_string = pq_getmsgstring(&input_message);
2930 pq_getmsgend(&input_message);
2932 exec_simple_query(query_string);
2938 case 'P': /* parse */
2940 const char *stmt_name;
2941 const char *query_string;
2943 Oid *paramTypes = NULL;
2945 stmt_name = pq_getmsgstring(&input_message);
2946 query_string = pq_getmsgstring(&input_message);
2947 numParams = pq_getmsgint(&input_message, 2);
2952 paramTypes = (Oid *) palloc(numParams * sizeof(Oid));
2953 for (i = 0; i < numParams; i++)
2954 paramTypes[i] = pq_getmsgint(&input_message, 4);
2956 pq_getmsgend(&input_message);
2958 exec_parse_message(query_string, stmt_name,
2959 paramTypes, numParams);
2963 case 'B': /* bind */
2966 * this message is complex enough that it seems best to
2967 * put the field extraction out-of-line
2969 exec_bind_message(&input_message);
2972 case 'E': /* execute */
2974 const char *portal_name;
2977 portal_name = pq_getmsgstring(&input_message);
2978 max_rows = pq_getmsgint(&input_message, 4);
2979 pq_getmsgend(&input_message);
2981 exec_execute_message(portal_name, max_rows);
2985 case 'F': /* fastpath function call */
2986 /* Tell the collector what we're doing */
2987 pgstat_report_activity("<FASTPATH> function call");
2989 /* start an xact for this function invocation */
2990 start_xact_command();
2992 /* switch back to message context */
2993 MemoryContextSwitchTo(MessageContext);
2995 if (HandleFunctionRequest(&input_message) == EOF)
2997 /* lost frontend connection during F message input */
3000 * Reset whereToSendOutput to prevent ereport from
3001 * attempting to send any more messages to client.
3003 if (whereToSendOutput == Remote)
3004 whereToSendOutput = None;
3009 /* commit the function-invocation transaction */
3010 finish_xact_command();
3015 case 'C': /* close */
3018 const char *close_target;
3020 close_type = pq_getmsgbyte(&input_message);
3021 close_target = pq_getmsgstring(&input_message);
3022 pq_getmsgend(&input_message);
3027 if (close_target[0] != '\0')
3028 DropPreparedStatement(close_target, false);
3031 /* special-case the unnamed statement */
3032 unnamed_stmt_pstmt = NULL;
3033 if (unnamed_stmt_context)
3035 DropDependentPortals(unnamed_stmt_context);
3036 MemoryContextDelete(unnamed_stmt_context);
3038 unnamed_stmt_context = NULL;
3045 portal = GetPortalByName(close_target);
3046 if (PortalIsValid(portal))
3047 PortalDrop(portal, false);
3052 (errcode(ERRCODE_PROTOCOL_VIOLATION),
3053 errmsg("invalid CLOSE message subtype %d",
3058 if (whereToSendOutput == Remote)
3059 pq_putemptymessage('3'); /* CloseComplete */
3063 case 'D': /* describe */
3066 const char *describe_target;
3068 describe_type = pq_getmsgbyte(&input_message);
3069 describe_target = pq_getmsgstring(&input_message);
3070 pq_getmsgend(&input_message);
3072 switch (describe_type)
3075 exec_describe_statement_message(describe_target);
3078 exec_describe_portal_message(describe_target);
3082 (errcode(ERRCODE_PROTOCOL_VIOLATION),
3083 errmsg("invalid DESCRIBE message subtype %d",
3090 case 'H': /* flush */
3091 pq_getmsgend(&input_message);
3092 if (whereToSendOutput == Remote)
3096 case 'S': /* sync */
3097 pq_getmsgend(&input_message);
3098 finish_xact_command();
3103 * 'X' means that the frontend is closing down the socket.
3104 * EOF means unexpected loss of frontend connection.
3105 * Either way, perform normal shutdown.
3111 * Reset whereToSendOutput to prevent ereport from
3112 * attempting to send any more messages to client.
3114 if (whereToSendOutput == Remote)
3115 whereToSendOutput = None;
3118 * NOTE: if you are tempted to add more code here, DON'T!
3119 * Whatever you had in mind to do should be set up as an
3120 * on_proc_exit or on_shmem_exit callback, instead.
3121 * Otherwise it will fail to be called during other
3122 * backend-shutdown scenarios.
3124 proc_exit(!in_fatal_exit ? 0 : proc_exit_inprogress ||
3125 !IsUnderPostmaster);
3127 case 'd': /* copy data */
3128 case 'c': /* copy done */
3129 case 'f': /* copy fail */
3132 * Accept but ignore these messages, per protocol spec; we
3133 * probably got here because a COPY failed, and the
3134 * frontend is still sending data.
3140 (errcode(ERRCODE_PROTOCOL_VIOLATION),
3141 errmsg("invalid frontend message type %d",
3144 } /* end of input-reading loop */
3146 /* can't get here because the above loop never exits */
3149 return 1; /* keep compiler quiet */
3152 #ifndef HAVE_GETRUSAGE
3153 #include "rusagestub.h"
3155 #include <sys/resource.h>
3156 #endif /* HAVE_GETRUSAGE */
3158 static struct rusage Save_r;
3159 static struct timeval Save_t;
3164 getrusage(RUSAGE_SELF, &Save_r);
3165 gettimeofday(&Save_t, NULL);
3167 /* ResetTupleCount(); */
3171 ShowUsage(const char *title)
3174 struct timeval user,
3176 struct timeval elapse_t;
3180 getrusage(RUSAGE_SELF, &r);
3181 gettimeofday(&elapse_t, NULL);
3182 memcpy((char *) &user, (char *) &r.ru_utime, sizeof(user));
3183 memcpy((char *) &sys, (char *) &r.ru_stime, sizeof(sys));
3184 if (elapse_t.tv_usec < Save_t.tv_usec)
3187 elapse_t.tv_usec += 1000000;
3189 if (r.ru_utime.tv_usec < Save_r.ru_utime.tv_usec)
3191 r.ru_utime.tv_sec--;
3192 r.ru_utime.tv_usec += 1000000;
3194 if (r.ru_stime.tv_usec < Save_r.ru_stime.tv_usec)
3196 r.ru_stime.tv_sec--;
3197 r.ru_stime.tv_usec += 1000000;
3201 * the only stats we don't show here are for memory usage -- i can't
3202 * figure out how to interpret the relevant fields in the rusage
3203 * struct, and they change names across o/s platforms, anyway. if you
3204 * can figure out what the entries mean, you can somehow extract
3205 * resident set size, shared text size, and unshared data and stack
3208 initStringInfo(&str);
3210 appendStringInfo(&str, "! system usage stats:\n");
3211 appendStringInfo(&str,
3212 "!\t%ld.%06ld elapsed %ld.%06ld user %ld.%06ld system sec\n",
3213 (long) (elapse_t.tv_sec - Save_t.tv_sec),
3214 (long) (elapse_t.tv_usec - Save_t.tv_usec),
3215 (long) (r.ru_utime.tv_sec - Save_r.ru_utime.tv_sec),
3216 (long) (r.ru_utime.tv_usec - Save_r.ru_utime.tv_usec),
3217 (long) (r.ru_stime.tv_sec - Save_r.ru_stime.tv_sec),
3218 (long) (r.ru_stime.tv_usec - Save_r.ru_stime.tv_usec));
3219 appendStringInfo(&str,
3220 "!\t[%ld.%06ld user %ld.%06ld sys total]\n",
3222 (long) user.tv_usec,
3224 (long) sys.tv_usec);
3225 /* BeOS has rusage but only has some fields, and not these... */
3226 #if defined(HAVE_GETRUSAGE)
3227 appendStringInfo(&str,
3228 "!\t%ld/%ld [%ld/%ld] filesystem blocks in/out\n",
3229 r.ru_inblock - Save_r.ru_inblock,
3230 /* they only drink coffee at dec */
3231 r.ru_oublock - Save_r.ru_oublock,
3232 r.ru_inblock, r.ru_oublock);
3233 appendStringInfo(&str,
3234 "!\t%ld/%ld [%ld/%ld] page faults/reclaims, %ld [%ld] swaps\n",
3235 r.ru_majflt - Save_r.ru_majflt,
3236 r.ru_minflt - Save_r.ru_minflt,
3237 r.ru_majflt, r.ru_minflt,
3238 r.ru_nswap - Save_r.ru_nswap,
3240 appendStringInfo(&str,
3241 "!\t%ld [%ld] signals rcvd, %ld/%ld [%ld/%ld] messages rcvd/sent\n",
3242 r.ru_nsignals - Save_r.ru_nsignals,
3244 r.ru_msgrcv - Save_r.ru_msgrcv,
3245 r.ru_msgsnd - Save_r.ru_msgsnd,
3246 r.ru_msgrcv, r.ru_msgsnd);
3247 appendStringInfo(&str,
3248 "!\t%ld/%ld [%ld/%ld] voluntary/involuntary context switches\n",
3249 r.ru_nvcsw - Save_r.ru_nvcsw,
3250 r.ru_nivcsw - Save_r.ru_nivcsw,
3251 r.ru_nvcsw, r.ru_nivcsw);
3252 #endif /* HAVE_GETRUSAGE */
3254 bufusage = ShowBufferUsage();
3255 appendStringInfo(&str, "! buffer usage stats:\n%s", bufusage);
3258 /* remove trailing newline */
3259 if (str.data[str.len - 1] == '\n')
3260 str.data[--str.len] = '\0';
3263 (errmsg_internal("%s", title),
3264 errdetail("%s", str.data)));
3270 * on_proc_exit handler to log end of session
3273 log_disconnections(int code, Datum arg)
3275 Port *port = MyProcPort;
3277 int hours, minutes, seconds;
3279 char session_time[20];
3280 char uname[6+NAMEDATALEN];
3281 char dbname[10+NAMEDATALEN];
3282 char remote_host[7 + NI_MAXHOST];
3283 char remote_port[7 + NI_MAXSERV];
3285 snprintf(uname, sizeof(uname)," user=%s",port->user_name);
3286 snprintf(dbname, sizeof(dbname)," database=%s",port->database_name);
3287 snprintf(remote_host,sizeof(remote_host)," host=%s",
3289 snprintf(remote_port,sizeof(remote_port)," port=%s",port->remote_port);
3292 gettimeofday(&end,NULL);
3294 if (end.tv_usec < port->session_start.tv_usec)
3297 end.tv_usec += 1000000;
3299 end.tv_sec -= port->session_start.tv_sec;
3300 end.tv_usec -= port->session_start.tv_usec;
3302 hours = end.tv_sec / 3600;
3304 minutes = end.tv_sec / 60;
3305 seconds = end.tv_sec % 60;
3307 /* if time has gone backwards for some reason say so, or print time */
3310 snprintf(session_time,sizeof(session_time),"negative!");
3312 /* for stricter accuracy here we could round - this is close enough */
3313 snprintf(session_time, sizeof(session_time),
3314 "%d:%02d:%02d.%02d",
3315 hours, minutes, seconds, (int) (end.tv_usec/10000));
3319 (errmsg("disconnection: session time: %s%s%s%s%s",
3320 session_time,uname,dbname,remote_host,remote_port)));