FORMAT <replaceable class="parameter">format_name</replaceable>
OIDS [ <replaceable class="parameter">boolean</replaceable> ]
+ FREEZE [ <replaceable class="parameter">boolean</replaceable> ]
DELIMITER '<replaceable class="parameter">delimiter_character</replaceable>'
NULL '<replaceable class="parameter">null_string</replaceable>'
HEADER [ <replaceable class="parameter">boolean</replaceable> ]
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><literal>FREEZE</literal></term>
+ <listitem>
+ <para>
+ Specifies copying the data with rows already frozen, just as they
+ would be after running the <command>VACUUM FREEZE</> command.
+ This is intended as a performance option for initial data loading.
+ Rows will be frozen only if the table being loaded has been created
+ in the current subtransaction, there are no cursors open and there
+ are no older snapshots held by this transaction. If those conditions
+ are not met the command will continue without error though will not
+ freeze rows.
+ </para>
+ <para>
+ Note that all sessions will immediately be able to see the data
+ once it has been successfully loaded. This violates the normal rules
+ of MVCC visibility and by specifying this option the user acknowledges
+ explicitly that this is understood.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><literal>DELIMITER</literal></term>
<listitem>
* The HEAP_INSERT_SKIP_FSM option is passed directly to
* RelationGetBufferForTuple, which see for more info.
*
+ * HEAP_INSERT_COMMITTED should only be specified for inserts into
+ * relfilenodes created during the current subtransaction and when
+ * there are no prior snapshots or pre-existing portals open.
+ *
+ * HEAP_INSERT_FROZEN only has meaning when HEAP_INSERT_COMMITTED is
+ * also set. This causes rows to be frozen, which is an MVCC violation
+ * and requires explicit options chosen by user.
+ *
* Note that these options will be applied when inserting into the heap's
* TOAST table, too, if the tuple requires any out-of-line data.
*
tup->t_data->t_infomask &= ~(HEAP_XACT_MASK);
tup->t_data->t_infomask2 &= ~(HEAP2_XACT_MASK);
tup->t_data->t_infomask |= HEAP_XMAX_INVALID;
- HeapTupleHeaderSetXmin(tup->t_data, xid);
+ if (options & HEAP_INSERT_COMMITTED)
+ {
+ tup->t_data->t_infomask |= HEAP_XMIN_COMMITTED;
+ if (options & HEAP_INSERT_FROZEN)
+ HeapTupleHeaderSetXmin(tup->t_data, FrozenTransactionId);
+ }
+ else
+ HeapTupleHeaderSetXmin(tup->t_data, xid);
HeapTupleHeaderSetCmin(tup->t_data, cid);
HeapTupleHeaderSetXmax(tup->t_data, 0); /* for cleanliness */
tup->t_tableOid = RelationGetRelid(relation);
#include "utils/builtins.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
+#include "utils/portal.h"
#include "utils/rel.h"
#include "utils/snapmgr.h"
char *filename; /* filename, or NULL for STDIN/STDOUT */
bool binary; /* binary format? */
bool oids; /* include OIDs? */
+ bool freeze; /* freeze rows on loading? */
bool csv_mode; /* Comma Separated Value format? */
bool header_line; /* CSV header line? */
char *null_print; /* NULL marker string (server encoding!) */
errmsg("conflicting or redundant options")));
cstate->oids = defGetBoolean(defel);
}
+ else if (strcmp(defel->defname, "freeze") == 0)
+ {
+ if (cstate->freeze)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("conflicting or redundant options")));
+ cstate->freeze = defGetBoolean(defel);
+ }
else if (strcmp(defel->defname, "delimiter") == 0)
{
if (cstate->delim)
hi_options |= HEAP_INSERT_SKIP_FSM;
if (!XLogIsNeeded())
hi_options |= HEAP_INSERT_SKIP_WAL;
+
+ /*
+ * Optimize if new relfilenode was created in this subxact or
+ * one of its committed children and we won't see those rows later
+ * as part of an earlier scan or command. This ensures that if this
+ * subtransaction aborts then the frozen rows won't be visible
+ * after xact cleanup. Note that the stronger test of exactly
+ * which subtransaction created it is crucial for correctness
+ * of this optimisation.
+ */
+ if (ThereAreNoPriorRegisteredSnapshots() &&
+ ThereAreNoReadyPortals() &&
+ cstate->rel->rd_newRelfilenodeSubid == GetCurrentSubTransactionId())
+ {
+ hi_options |= HEAP_INSERT_COMMITTED;
+ if (cstate->freeze)
+ hi_options |= HEAP_INSERT_FROZEN;
+ }
}
+ if (cstate->freeze && (hi_options & HEAP_INSERT_FROZEN) == 0)
+ ereport(NOTICE,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("FREEZE option specified but pre-conditions not met")));
+
/*
* We need a ResultRelInfo so we can use the regular executor's
* index-entry-making machinery. (There used to be a huge amount of code
{
$$ = makeDefElem("oids", (Node *)makeInteger(TRUE));
}
+ | FREEZE
+ {
+ $$ = makeDefElem("freeze", (Node *)makeInteger(TRUE));
+ }
| DELIMITER opt_as Sconst
{
$$ = makeDefElem("delimiter", (Node *)makeString($3));
return (Datum) 0;
}
+
+bool
+ThereAreNoReadyPortals(void)
+{
+ HASH_SEQ_STATUS status;
+ PortalHashEnt *hentry;
+
+ hash_seq_init(&status, PortalHashTable);
+
+ while ((hentry = (PortalHashEnt *) hash_seq_search(&status)) != NULL)
+ {
+ Portal portal = hentry->portal;
+
+ if (portal->status == PORTAL_READY)
+ return false;
+ }
+
+ return true;
+}
FreeDir(s_dir);
}
+
+bool
+ThereAreNoPriorRegisteredSnapshots(void)
+{
+ if (RegisteredSnapshots <= 1)
+ return true;
+
+ return false;
+}
/* "options" flag bits for heap_insert */
#define HEAP_INSERT_SKIP_WAL 0x0001
#define HEAP_INSERT_SKIP_FSM 0x0002
+#define HEAP_INSERT_COMMITTED 0x0004
+#define HEAP_INSERT_FROZEN 0x0008
typedef struct BulkInsertStateData *BulkInsertState;
extern Node *PortalListGetPrimaryStmt(List *stmts);
extern void PortalCreateHoldStore(Portal portal);
extern void PortalHashTableDeleteAll(void);
+extern bool ThereAreNoReadyPortals(void);
#endif /* PORTAL_H */
extern void ImportSnapshot(const char *idstr);
extern bool XactHasExportedSnapshots(void);
extern void DeleteAllExportedSnapshotFiles(void);
+extern bool ThereAreNoPriorRegisteredSnapshots(void);
#endif /* SNAPMGR_H */
|
(4 rows)
+CREATE TABLE vistest (LIKE testeoc);
+BEGIN;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+SELECT * FROM vistest;
+ a
+---
+ a
+ b
+(2 rows)
+
+SAVEPOINT s1;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+SELECT * FROM vistest;
+ a
+---
+ d
+ e
+(2 rows)
+
+COMMIT;
+BEGIN;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV FREEZE;
+SELECT * FROM vistest;
+ a
+---
+ a
+ b
+(2 rows)
+
+SAVEPOINT s1;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV FREEZE;
+SELECT * FROM vistest;
+ a
+---
+ d
+ e
+(2 rows)
+
+COMMIT;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV FREEZE;
+NOTICE: FREEZE option specified but pre-conditions not met
+SELECT * FROM vistest;
+ a
+---
+ a
+ b
+(2 rows)
+
+BEGIN;
+INSERT INTO vistest VALUES ('z');
+SAVEPOINT s1;
+TRUNCATE vistest;
+ROLLBACK TO SAVEPOINT s1;
+-- FREEZE should be silently ignored here
+COPY vistest FROM stdin CSV FREEZE;
+NOTICE: FREEZE option specified but pre-conditions not met
+SELECT * FROM vistest;
+ a
+---
+ a
+ b
+ z
+ d
+ e
+(5 rows)
+
+COMMIT;
+CREATE FUNCTION truncate_in_subxact() RETURNS VOID AS
+$$
+BEGIN
+ SELECT * FROM nonexistent;
+EXCEPTION
+ WHEN OTHERS THEN
+ TRUNCATE vistest;
+END;
+$$ language plpgsql;
+BEGIN;
+INSERT INTO vistest VALUES ('z');
+SELECT truncate_in_subxact();
+ truncate_in_subxact
+---------------------
+
+(1 row)
+
+COPY vistest FROM stdin CSV FREEZE;
+SELECT * FROM vistest;
+ a
+---
+ d
+ e
+(2 rows)
+
+COMMIT;
+SELECT * FROM vistest;
+ a
+---
+ d
+ e
+(2 rows)
+
+DROP TABLE vistest;
DROP TABLE x, y;
DROP FUNCTION fn_x_before();
DROP FUNCTION fn_x_after();
SELECT * FROM testnull;
+CREATE TABLE vistest (LIKE testeoc);
+BEGIN;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+a
+b
+\.
+SELECT * FROM vistest;
+SAVEPOINT s1;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+d
+e
+\.
+SELECT * FROM vistest;
+COMMIT;
+
+BEGIN;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV FREEZE;
+a
+b
+\.
+SELECT * FROM vistest;
+SAVEPOINT s1;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV FREEZE;
+d
+e
+\.
+SELECT * FROM vistest;
+COMMIT;
+BEGIN;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV FREEZE;
+x
+y
+\.
+SELECT * FROM vistest;
+COMMIT;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV FREEZE;
+p
+g
+\.
+BEGIN;
+INSERT INTO vistest VALUES ('z');
+SAVEPOINT s1;
+TRUNCATE vistest;
+ROLLBACK TO SAVEPOINT s1;
+-- FREEZE should be silently ignored here
+COPY vistest FROM stdin CSV FREEZE;
+d
+e
+\.
+SELECT * FROM vistest;
+COMMIT;
+CREATE FUNCTION truncate_in_subxact() RETURNS VOID AS
+$$
+BEGIN
+ SELECT * FROM nonexistent;
+EXCEPTION
+ WHEN OTHERS THEN
+ TRUNCATE vistest;
+END;
+$$ language plpgsql;
+BEGIN;
+INSERT INTO vistest VALUES ('z');
+SELECT truncate_in_subxact();
+COPY vistest FROM stdin CSV FREEZE;
+d
+e
+\.
+SELECT * FROM vistest;
+COMMIT;
+SELECT * FROM vistest;
+DROP TABLE vistest;
+DROP FUNCTION truncate_in_subxact();
DROP TABLE x, y;
DROP FUNCTION fn_x_before();
DROP FUNCTION fn_x_after();
projects / postgresql / commitdiff