From: Tom Lane Date: Wed, 2 Oct 2002 21:30:13 +0000 (+0000) Subject: Re-enable pg_resetxlog to accept -l values in hexadecimal (it used to X-Git-Tag: REL7_3~362 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=71e74a2f587ab8847e99b431b40d6acf62144128;p=postgresql Re-enable pg_resetxlog to accept -l values in hexadecimal (it used to be able to do that, but the ability seems to have got lost in the shuffle). Add a -o nextOID switch for completeness. Improve the documentation to explain how and why to use these switches. --- diff --git a/doc/src/sgml/ref/pg_resetxlog.sgml b/doc/src/sgml/ref/pg_resetxlog.sgml index 00b24fe016..61fce46a17 100644 --- a/doc/src/sgml/ref/pg_resetxlog.sgml +++ b/doc/src/sgml/ref/pg_resetxlog.sgml @@ -1,5 +1,5 @@ @@ -12,7 +12,7 @@ PostgreSQL documentation pg_resetxlog - reset write-ahead log file and optionally the pg_control file + reset write-ahead log and pg_control contents @@ -20,6 +20,7 @@ PostgreSQL documentation pg_resetxlog -f -n + -o oid -x xid -l fileid,seg datadir @@ -29,8 +30,9 @@ PostgreSQL documentation Description - pg_resetxlog clears the write-ahead log file and - optionally the pg_control file. This function is sometimes + pg_resetxlog clears the write-ahead log and + optionally resets some fields in the pg_control file. This + function is sometimes needed if these files have become corrupted. It should be used only as a last resort, when the server will not start due to such corruption. @@ -55,14 +57,45 @@ PostgreSQL documentation If pg_resetxlog complains that it cannot determine valid data for pg_control, you can force it to proceed anyway - by specifying the -f (force) switch. In this case plausible values - will be substituted for the missing data. If -f is used then + by specifying the -f (force) switch. In this case plausible + values will be substituted for the missing data. Most of the fields can be + expected to match, but manual assistance may be needed for the next OID, + next transaction ID, WAL starting address, and database locale fields. + The first three of these can be set using the switches discussed below. + pg_resetxlog's own environment is the source for its + guess at the locale fields; take care that LANG and so forth + match the environment that initdb was run in. + If you are not able to determine correct values for all these fields, + -f can still be used, but the recovered database must be treated with even more suspicion than usual --- an immediate dump and reload is imperative. Do not execute any data-modifying operations in the database before you dump, as any such action is likely to make the corruption worse. + + The -o, -x, and -l switches allow + the next OID, next transaction ID, and WAL starting address values to + be set manually. These are only needed when + pg_resetxlog is unable to determine appropriate values + by reading pg_control. A safe value for the + next transaction ID may be determined by looking for the largest + file name in $PGDATA/pg_clog, adding one, + and then multiplying by 1048576. Note that the file names are in + hexadecimal. It is usually easiest to specify the switch value in + hexadecimal too. For example, if 0011 is the largest entry + in pg_clog, -x 0x1200000 will work (five trailing + zeroes provide the proper multiplier). + The WAL starting address should be + larger than any file number currently existing in + $PGDATA/pg_xlog. These also are in hex, and + have two parts. For example, if 000000FF0000003A is the + largest entry in pg_xlog, -l 0xFF,0x3B will work. + There is no comparably easy way to determine a next OID that's beyond + the largest one in the database, but fortunately it is not critical to + get the next-OID setting right. + + The -n (no operation) switch instructs pg_resetxlog to print the values reconstructed from @@ -70,12 +103,6 @@ PostgreSQL documentation This is mainly a debugging tool, but may be useful as a sanity check before allowing pg_resetxlog to proceed for real. - - - The -x and -l switches are intended for use by - pg_upgrade. In most cases they should not be used in - manual recovery operations. - diff --git a/src/bin/pg_resetxlog/pg_resetxlog.c b/src/bin/pg_resetxlog/pg_resetxlog.c index 56621cd556..81fb79b3a3 100644 --- a/src/bin/pg_resetxlog/pg_resetxlog.c +++ b/src/bin/pg_resetxlog/pg_resetxlog.c @@ -23,7 +23,7 @@ * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $Header: /cvsroot/pgsql/src/bin/pg_resetxlog/pg_resetxlog.c,v 1.6 2002/10/02 19:45:47 tgl Exp $ + * $Header: /cvsroot/pgsql/src/bin/pg_resetxlog/pg_resetxlog.c,v 1.7 2002/10/02 21:30:13 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -90,8 +90,11 @@ main(int argc, char *argv[]) bool force = false; bool noupdate = false; TransactionId set_xid = 0; + Oid set_oid = 0; uint32 minXlogId = 0, minXlogSeg = 0; + char *endptr; + char *endptr2; char *DataDir; int fd; char path[MAXPGPATH]; @@ -122,7 +125,7 @@ main(int argc, char *argv[]) } - while ((c = getopt(argc, argv, "fl:nx:")) != -1) + while ((c = getopt(argc, argv, "fl:no:x:")) != -1) { switch (c) { @@ -135,7 +138,13 @@ main(int argc, char *argv[]) break; case 'x': - set_xid = strtoul(optarg, NULL, 0); + set_xid = strtoul(optarg, &endptr, 0); + if (endptr == optarg || *endptr != '\0') + { + fprintf(stderr, _("%s: invalid argument for -x option\n"), progname); + fprintf(stderr, _("Try '%s --help' for more information.\n"), progname); + exit(1); + } if (set_xid == 0) { fprintf(stderr, _("%s: transaction ID (-x) must not be 0\n"), progname); @@ -143,8 +152,31 @@ main(int argc, char *argv[]) } break; + case 'o': + set_oid = strtoul(optarg, &endptr, 0); + if (endptr == optarg || *endptr != '\0') + { + fprintf(stderr, _("%s: invalid argument for -o option\n"), progname); + fprintf(stderr, _("Try '%s --help' for more information.\n"), progname); + exit(1); + } + if (set_oid == 0) + { + fprintf(stderr, _("%s: OID (-o) must not be 0\n"), progname); + exit(1); + } + break; + case 'l': - if (sscanf(optarg, "%u,%u", &minXlogId, &minXlogSeg) != 2) + minXlogId = strtoul(optarg, &endptr, 0); + if (endptr == optarg || *endptr != ',') + { + fprintf(stderr, _("%s: invalid argument for -l option\n"), progname); + fprintf(stderr, _("Try '%s --help' for more information.\n"), progname); + exit(1); + } + minXlogSeg = strtoul(endptr+1, &endptr2, 0); + if (endptr2 == endptr+1 || *endptr2 != '\0') { fprintf(stderr, _("%s: invalid argument for -l option\n"), progname); fprintf(stderr, _("Try '%s --help' for more information.\n"), progname); @@ -198,6 +230,24 @@ main(int argc, char *argv[]) if (!ReadControlFile()) GuessControlValues(); + /* + * Adjust fields if required by switches. (Do this now so that + * printout, if any, includes these values.) + */ + if (set_xid != 0) + ControlFile.checkPointCopy.nextXid = set_xid; + + if (set_oid != 0) + ControlFile.checkPointCopy.nextOid = set_oid; + + if (minXlogId > ControlFile.logId || + (minXlogId == ControlFile.logId && + minXlogSeg > ControlFile.logSeg)) + { + ControlFile.logId = minXlogId; + ControlFile.logSeg = minXlogSeg; + } + /* * If we had to guess anything, and -f was not given, just print the * guessed values and exit. Also print if -n is given. @@ -227,19 +277,7 @@ main(int argc, char *argv[]) /* * Else, do the dirty deed. - * - * First adjust fields if required by switches. */ - if (set_xid != 0) - ControlFile.checkPointCopy.nextXid = set_xid; - - if (minXlogId > ControlFile.logId || - (minXlogId == ControlFile.logId && minXlogSeg > ControlFile.logSeg)) - { - ControlFile.logId = minXlogId; - ControlFile.logSeg = minXlogSeg; - } - RewriteControlFile(); KillExistingXLOG(); WriteEmptyXLOG(); @@ -659,6 +697,7 @@ usage(void) printf(_(" -f force update to be done\n")); printf(_(" -l FILEID,SEG force minimum WAL starting location for new transaction log\n")); printf(_(" -n no update, just show extracted control values (for testing)\n")); + printf(_(" -o OID set next OID\n")); printf(_(" -x XID set next transaction ID\n")); printf(_("\nReport bugs to .\n")); }