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/*-------------------------------------------------------------------------
*
* vacuumlo.c
* This removes orphaned large objects from a database.
*
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/contrib/vacuumlo/vacuumlo.c,v 1.8 2001/01/24 19:42:45 momjian Exp $
*
*-------------------------------------------------------------------------
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include "libpq-fe.h"
#include "libpq/libpq-fs.h"
#define atooid(x) ((Oid) strtoul((x), NULL, 10))
#define BUFSIZE 1024
int vacuumlo(char *, int);
/*
* This vacuums LOs of one database. It returns 0 on success, -1 on failure.
*/
int
vacuumlo(char *database, int verbose)
{
PGconn *conn;
PGresult *res,
*res2;
char buf[BUFSIZE];
int matched;
int deleted;
int i;
conn = PQsetdb(NULL, NULL, NULL, NULL, database);
/* 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 (verbose)
fprintf(stdout, "Connected to %s\n", database);
/*
* First we create and populate the LO temp table
*/
buf[0] = '\0';
strcat(buf, "SELECT DISTINCT loid AS lo ");
strcat(buf, "INTO TEMP TABLE vacuum_l ");
strcat(buf, "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 who have columns of type oid.
*
* NOTE: the temp table formed above is ignored, because its real
* table name will be pg_something. Also, pg_largeobject will be
* ignored. 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 c.relname, a.attname ");
strcat(buf, "FROM pg_class c, pg_attribute a, pg_type t ");
strcat(buf, "WHERE a.attnum > 0 ");
strcat(buf, " AND a.attrelid = c.oid ");
strcat(buf, " AND a.atttypid = t.oid ");
strcat(buf, " AND t.typname = 'oid' ");
strcat(buf, " AND c.relkind = 'r'");
strcat(buf, " AND c.relname 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 *table,
*field;
table = PQgetvalue(res, i, 0);
field = PQgetvalue(res, i, 1);
if (verbose)
fprintf(stdout, "Checking %s in %s\n", field, table);
/*
* We use a DELETE with implicit join for efficiency. This
* is a Postgres-ism and not portable to other DBMSs, but
* then this whole program is a Postgres-ism.
*/
sprintf(buf, "DELETE FROM vacuum_l WHERE lo = \"%s\".\"%s\" ",
table, field);
res2 = PQexec(conn, buf);
if (PQresultStatus(res2) != PGRES_COMMAND_OK)
{
fprintf(stderr, "Failed to check %s in table %s:\n",
field, 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 (verbose)
{
fprintf(stdout, "\rRemoving lo %6u ", lo);
fflush(stdout);
}
if (lo_unlink(conn, lo) < 0)
{
fprintf(stderr, "\nFailed to remove lo %u: ", lo);
fprintf(stderr, "%s", PQerrorMessage(conn));
}
else
deleted++;
}
PQclear(res);
/*
* That's all folks!
*/
res = PQexec(conn, "end");
PQclear(res);
PQfinish(conn);
if (verbose)
fprintf(stdout, "\rRemoved %d large objects from %s.\n",
deleted, database);
return 0;
}
int
main(int argc, char **argv)
{
int verbose = 0;
int arg;
int rc = 0;
if (argc < 2)
{
fprintf(stderr, "Usage: %s [-v] database_name [db2 ... dbn]\n",
argv[0]);
exit(1);
}
for (arg = 1; arg < argc; arg++)
{
if (strcmp("-v", argv[arg]) == 0)
verbose = !verbose;
else
rc += (vacuumlo(argv[arg], verbose) != 0);
}
return rc;
}
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