postgresql/contrib/vacuumlo/vacuumlo.c
2005-10-15 02:49:52 +00:00

376 lines
8.4 KiB
C

/*-------------------------------------------------------------------------
*
* vacuumlo.c
* This removes orphaned large objects from a database.
*
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/contrib/vacuumlo/vacuumlo.c,v 1.30 2005/10/15 02:49:08 momjian Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres_fe.h"
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#ifdef HAVE_TERMIOS_H
#include <termios.h>
#endif
#include "libpq-fe.h"
#include "libpq/libpq-fs.h"
#define atooid(x) ((Oid) strtoul((x), NULL, 10))
#define BUFSIZE 1024
extern char *optarg;
extern int optind,
opterr,
optopt;
struct _param
{
char *pg_user;
int pg_prompt;
char *pg_port;
char *pg_host;
int verbose;
int dry_run;
};
int vacuumlo(char *, struct _param *);
void usage(void);
/*
* This vacuums LOs of one database. It returns 0 on success, -1 on failure.
*/
int
vacuumlo(char *database, struct _param * param)
{
PGconn *conn;
PGresult *res,
*res2;
char buf[BUFSIZE];
int matched;
int deleted;
int i;
char *password = NULL;
if (param->pg_prompt)
{
password = simple_prompt("Password: ", 32, 0);
if (!password)
{
fprintf(stderr, "failed to get password\n");
exit(1);
}
}
conn = PQsetdbLogin(param->pg_host,
param->pg_port,
NULL,
NULL,
database,
param->pg_user,
password
);
/* check to see that the backend connection was successfully made */
if (PQstatus(conn) == CONNECTION_BAD)
{
fprintf(stderr, "Connection to database '%s' failed:\n", database);
fprintf(stderr, "%s", PQerrorMessage(conn));
PQfinish(conn);
return -1;
}
if (param->verbose)
{
fprintf(stdout, "Connected to %s\n", database);
if (param->dry_run)
fprintf(stdout, "Test run: no large objects will be removed!\n");
}
/*
* Don't get fooled by any non-system catalogs
*/
res = PQexec(conn, "SET search_path = pg_catalog");
if (PQresultStatus(res) != PGRES_COMMAND_OK)
{
fprintf(stderr, "Failed to set search_path:\n");
fprintf(stderr, "%s", PQerrorMessage(conn));
PQclear(res);
PQfinish(conn);
return -1;
}
PQclear(res);
/*
* First we create and populate the LO temp table
*/
buf[0] = '\0';
strcat(buf, "CREATE TEMP TABLE vacuum_l AS ");
strcat(buf, "SELECT DISTINCT loid AS lo FROM pg_largeobject ");
res = PQexec(conn, buf);
if (PQresultStatus(res) != PGRES_COMMAND_OK)
{
fprintf(stderr, "Failed to create temp table:\n");
fprintf(stderr, "%s", PQerrorMessage(conn));
PQclear(res);
PQfinish(conn);
return -1;
}
PQclear(res);
/*
* Vacuum the temp table so that planner will generate decent plans for
* the DELETEs below.
*/
buf[0] = '\0';
strcat(buf, "VACUUM ANALYZE vacuum_l");
res = PQexec(conn, buf);
if (PQresultStatus(res) != PGRES_COMMAND_OK)
{
fprintf(stderr, "Failed to vacuum temp table:\n");
fprintf(stderr, "%s", PQerrorMessage(conn));
PQclear(res);
PQfinish(conn);
return -1;
}
PQclear(res);
/*
* Now find any candidate tables that have columns of type oid.
*
* NOTE: we ignore system tables and temp tables by the expedient of
* rejecting tables in schemas named 'pg_*'. In particular, the temp
* table formed above is ignored, and pg_largeobject will be too. If
* either of these were scanned, obviously we'd end up with nothing to
* delete...
*
* NOTE: the system oid column is ignored, as it has attnum < 1. This
* shouldn't matter for correctness, but it saves time.
*/
buf[0] = '\0';
strcat(buf, "SELECT s.nspname, c.relname, a.attname ");
strcat(buf, "FROM pg_class c, pg_attribute a, pg_namespace s, pg_type t ");
strcat(buf, "WHERE a.attnum > 0 AND NOT a.attisdropped ");
strcat(buf, " AND a.attrelid = c.oid ");
strcat(buf, " AND a.atttypid = t.oid ");
strcat(buf, " AND c.relnamespace = s.oid ");
strcat(buf, " AND t.typname in ('oid', 'lo') ");
strcat(buf, " AND c.relkind = 'r'");
strcat(buf, " AND s.nspname NOT LIKE 'pg\\\\_%'");
res = PQexec(conn, buf);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
fprintf(stderr, "Failed to find OID columns:\n");
fprintf(stderr, "%s", PQerrorMessage(conn));
PQclear(res);
PQfinish(conn);
return -1;
}
for (i = 0; i < PQntuples(res); i++)
{
char *schema,
*table,
*field;
schema = PQgetvalue(res, i, 0);
table = PQgetvalue(res, i, 1);
field = PQgetvalue(res, i, 2);
if (param->verbose)
fprintf(stdout, "Checking %s in %s.%s\n", field, schema, table);
/*
* The "IN" construct used here was horribly inefficient before
* Postgres 7.4, but should be now competitive if not better than the
* bogus join we used before.
*/
snprintf(buf, BUFSIZE,
"DELETE FROM vacuum_l "
"WHERE lo IN (SELECT \"%s\" FROM \"%s\".\"%s\")",
field, schema, table);
res2 = PQexec(conn, buf);
if (PQresultStatus(res2) != PGRES_COMMAND_OK)
{
fprintf(stderr, "Failed to check %s in table %s.%s:\n",
field, schema, table);
fprintf(stderr, "%s", PQerrorMessage(conn));
PQclear(res2);
PQclear(res);
PQfinish(conn);
return -1;
}
PQclear(res2);
}
PQclear(res);
/*
* Run the actual deletes in a single transaction. Note that this would
* be a bad idea in pre-7.1 Postgres releases (since rolling back a table
* delete used to cause problems), but it should be safe now.
*/
res = PQexec(conn, "begin");
PQclear(res);
/*
* Finally, those entries remaining in vacuum_l are orphans.
*/
buf[0] = '\0';
strcat(buf, "SELECT lo ");
strcat(buf, "FROM vacuum_l");
res = PQexec(conn, buf);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
fprintf(stderr, "Failed to read temp table:\n");
fprintf(stderr, "%s", PQerrorMessage(conn));
PQclear(res);
PQfinish(conn);
return -1;
}
matched = PQntuples(res);
deleted = 0;
for (i = 0; i < matched; i++)
{
Oid lo = atooid(PQgetvalue(res, i, 0));
if (param->verbose)
{
fprintf(stdout, "\rRemoving lo %6u ", lo);
fflush(stdout);
}
if (param->dry_run == 0)
{
if (lo_unlink(conn, lo) < 0)
{
fprintf(stderr, "\nFailed to remove lo %u: ", lo);
fprintf(stderr, "%s", PQerrorMessage(conn));
}
else
deleted++;
}
else
deleted++;
}
PQclear(res);
/*
* That's all folks!
*/
res = PQexec(conn, "end");
PQclear(res);
PQfinish(conn);
if (param->verbose)
fprintf(stdout, "\r%s %d large objects from %s.\n",
(param->dry_run ? "Would remove" : "Removed"), deleted, database);
return 0;
}
void
usage(void)
{
fprintf(stdout, "vacuumlo removes unreferenced large objects from databases\n\n");
fprintf(stdout, "Usage:\n vacuumlo [options] dbname [dbname ...]\n\n");
fprintf(stdout, "Options:\n");
fprintf(stdout, " -v\t\tWrite a lot of progress messages\n");
fprintf(stdout, " -n\t\tDon't remove large objects, just show what would be done\n");
fprintf(stdout, " -U username\tUsername to connect as\n");
fprintf(stdout, " -W\t\tPrompt for password\n");
fprintf(stdout, " -h hostname\tDatabase server host\n");
fprintf(stdout, " -p port\tDatabase server port\n\n");
}
int
main(int argc, char **argv)
{
int rc = 0;
struct _param param;
int c;
int port;
/* Parameter handling */
param.pg_user = NULL;
param.pg_prompt = 0;
param.pg_host = NULL;
param.pg_port = NULL;
param.verbose = 0;
param.dry_run = 0;
while (1)
{
c = getopt(argc, argv, "?h:U:p:vnW");
if (c == -1)
break;
switch (c)
{
case '?':
if (optopt == '?')
{
usage();
exit(0);
}
exit(1);
case ':':
exit(1);
case 'v':
param.verbose = 1;
break;
case 'n':
param.dry_run = 1;
param.verbose = 1;
break;
case 'U':
param.pg_user = strdup(optarg);
break;
case 'W':
param.pg_prompt = 1;
break;
case 'p':
port = strtol(optarg, NULL, 10);
if ((port < 1) || (port > 65535))
{
fprintf(stderr, "[%s]: invalid port number '%s'\n", argv[0], optarg);
exit(1);
}
param.pg_port = strdup(optarg);
break;
case 'h':
param.pg_host = strdup(optarg);
break;
}
}
/* No database given? Show usage */
if (optind >= argc)
{
fprintf(stderr, "vacuumlo: missing required argument: database name\n");
fprintf(stderr, "Try 'vacuumlo -?' for help.\n");
exit(1);
}
for (c = optind; c < argc; c++)
{
/* Work on selected database */
rc += (vacuumlo(argv[c], &param) != 0);
}
return rc;
}