postgresql/src/bin/pg_controldata/pg_controldata.c
Tom Lane 25ec228ef7 Track the current XID wrap limit (or more accurately, the oldest unfrozen
XID) in checkpoint records.  This eliminates the need to recompute the value
from scratch during database startup, which is one of the two remaining
reasons for the flatfile code to exist.  It should also simplify life for
hot-standby operation.

To avoid bloating the checkpoint records unreasonably, I switched from
tracking the oldest database by name to tracking it by OID.  This turns
out to save cycles in general (everywhere but the warning-generating
paths, which we hardly care about) and also helps us deal with the case
that the oldest database got dropped instead of being vacuumed.  The prior
coding might go for a long time without updating the wrap limit in that case,
which is bad because it might result in a lot of useless autovacuum activity.
2009-08-31 02:23:23 +00:00

229 lines
7.4 KiB
C

/*
* pg_controldata
*
* reads the data from $PGDATA/global/pg_control
*
* copyright (c) Oliver Elphick <olly@lfix.co.uk>, 2001;
* licence: BSD
*
* $PostgreSQL: pgsql/src/bin/pg_controldata/pg_controldata.c,v 1.44 2009/08/31 02:23:22 tgl Exp $
*/
#include "postgres_fe.h"
#include <unistd.h>
#include <time.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "catalog/pg_control.h"
static void
usage(const char *progname)
{
printf(_("%s displays control information of a PostgreSQL database cluster.\n\n"), progname);
printf
(
_(
"Usage:\n"
" %s [OPTION] [DATADIR]\n\n"
"Options:\n"
" --help show this help, then exit\n"
" --version output version information, then exit\n"
),
progname
);
printf(_("\nIf no data directory (DATADIR) is specified, "
"the environment variable PGDATA\nis used.\n\n"));
printf(_("Report bugs to <pgsql-bugs@postgresql.org>.\n"));
}
static const char *
dbState(DBState state)
{
switch (state)
{
case DB_STARTUP:
return _("starting up");
case DB_SHUTDOWNED:
return _("shut down");
case DB_SHUTDOWNING:
return _("shutting down");
case DB_IN_CRASH_RECOVERY:
return _("in crash recovery");
case DB_IN_ARCHIVE_RECOVERY:
return _("in archive recovery");
case DB_IN_PRODUCTION:
return _("in production");
}
return _("unrecognized status code");
}
int
main(int argc, char *argv[])
{
ControlFileData ControlFile;
int fd;
char ControlFilePath[MAXPGPATH];
char *DataDir;
pg_crc32 crc;
time_t time_tmp;
char pgctime_str[128];
char ckpttime_str[128];
char sysident_str[32];
const char *strftime_fmt = "%c";
const char *progname;
set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_controldata"));
progname = get_progname(argv[0]);
if (argc > 1)
{
if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
{
usage(progname);
exit(0);
}
if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
{
puts("pg_controldata (PostgreSQL) " PG_VERSION);
exit(0);
}
}
if (argc > 1)
DataDir = argv[1];
else
DataDir = getenv("PGDATA");
if (DataDir == NULL)
{
fprintf(stderr, _("%s: no data directory specified\n"), progname);
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
snprintf(ControlFilePath, MAXPGPATH, "%s/global/pg_control", DataDir);
if ((fd = open(ControlFilePath, O_RDONLY | PG_BINARY, 0)) == -1)
{
fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"),
progname, ControlFilePath, strerror(errno));
exit(2);
}
if (read(fd, &ControlFile, sizeof(ControlFileData)) != sizeof(ControlFileData))
{
fprintf(stderr, _("%s: could not read file \"%s\": %s\n"),
progname, ControlFilePath, strerror(errno));
exit(2);
}
close(fd);
/* Check the CRC. */
INIT_CRC32(crc);
COMP_CRC32(crc,
(char *) &ControlFile,
offsetof(ControlFileData, crc));
FIN_CRC32(crc);
if (!EQ_CRC32(crc, ControlFile.crc))
printf(_("WARNING: Calculated CRC checksum does not match value stored in file.\n"
"Either the file is corrupt, or it has a different layout than this program\n"
"is expecting. The results below are untrustworthy.\n\n"));
/*
* This slightly-chintzy coding will work as long as the control file
* timestamps are within the range of time_t; that should be the case in
* all foreseeable circumstances, so we don't bother importing the
* backend's timezone library into pg_controldata.
*
* Use variable for format to suppress overly-anal-retentive gcc warning
* about %c
*/
time_tmp = (time_t) ControlFile.time;
strftime(pgctime_str, sizeof(pgctime_str), strftime_fmt,
localtime(&time_tmp));
time_tmp = (time_t) ControlFile.checkPointCopy.time;
strftime(ckpttime_str, sizeof(ckpttime_str), strftime_fmt,
localtime(&time_tmp));
/*
* Format system_identifier separately to keep platform-dependent format
* code out of the translatable message string.
*/
snprintf(sysident_str, sizeof(sysident_str), UINT64_FORMAT,
ControlFile.system_identifier);
printf(_("pg_control version number: %u\n"),
ControlFile.pg_control_version);
if (ControlFile.pg_control_version % 65536 == 0 && ControlFile.pg_control_version / 65536 != 0)
printf(_("WARNING: possible byte ordering mismatch\n"
"The byte ordering used to store the pg_control file might not match the one\n"
"used by this program. In that case the results below would be incorrect, and\n"
"the PostgreSQL installation would be incompatible with this data directory.\n"));
printf(_("Catalog version number: %u\n"),
ControlFile.catalog_version_no);
printf(_("Database system identifier: %s\n"),
sysident_str);
printf(_("Database cluster state: %s\n"),
dbState(ControlFile.state));
printf(_("pg_control last modified: %s\n"),
pgctime_str);
printf(_("Latest checkpoint location: %X/%X\n"),
ControlFile.checkPoint.xlogid,
ControlFile.checkPoint.xrecoff);
printf(_("Prior checkpoint location: %X/%X\n"),
ControlFile.prevCheckPoint.xlogid,
ControlFile.prevCheckPoint.xrecoff);
printf(_("Latest checkpoint's REDO location: %X/%X\n"),
ControlFile.checkPointCopy.redo.xlogid,
ControlFile.checkPointCopy.redo.xrecoff);
printf(_("Latest checkpoint's TimeLineID: %u\n"),
ControlFile.checkPointCopy.ThisTimeLineID);
printf(_("Latest checkpoint's NextXID: %u/%u\n"),
ControlFile.checkPointCopy.nextXidEpoch,
ControlFile.checkPointCopy.nextXid);
printf(_("Latest checkpoint's NextOID: %u\n"),
ControlFile.checkPointCopy.nextOid);
printf(_("Latest checkpoint's NextMultiXactId: %u\n"),
ControlFile.checkPointCopy.nextMulti);
printf(_("Latest checkpoint's NextMultiOffset: %u\n"),
ControlFile.checkPointCopy.nextMultiOffset);
printf(_("Latest checkpoint's oldestXID: %u\n"),
ControlFile.checkPointCopy.oldestXid);
printf(_("Latest checkpoint's oldestXID's DB: %u\n"),
ControlFile.checkPointCopy.oldestXidDB);
printf(_("Time of latest checkpoint: %s\n"),
ckpttime_str);
printf(_("Minimum recovery ending location: %X/%X\n"),
ControlFile.minRecoveryPoint.xlogid,
ControlFile.minRecoveryPoint.xrecoff);
printf(_("Maximum data alignment: %u\n"),
ControlFile.maxAlign);
/* we don't print floatFormat since can't say much useful about it */
printf(_("Database block size: %u\n"),
ControlFile.blcksz);
printf(_("Blocks per segment of large relation: %u\n"),
ControlFile.relseg_size);
printf(_("WAL block size: %u\n"),
ControlFile.xlog_blcksz);
printf(_("Bytes per WAL segment: %u\n"),
ControlFile.xlog_seg_size);
printf(_("Maximum length of identifiers: %u\n"),
ControlFile.nameDataLen);
printf(_("Maximum columns in an index: %u\n"),
ControlFile.indexMaxKeys);
printf(_("Maximum size of a TOAST chunk: %u\n"),
ControlFile.toast_max_chunk_size);
printf(_("Date/time type storage: %s\n"),
(ControlFile.enableIntTimes ? _("64-bit integers") : _("floating-point numbers")));
printf(_("Float4 argument passing: %s\n"),
(ControlFile.float4ByVal ? _("by value") : _("by reference")));
printf(_("Float8 argument passing: %s\n"),
(ControlFile.float8ByVal ? _("by value") : _("by reference")));
return 0;
}