BUG #1756: PQexec eats huge amounts of memory

The following bug has been logged online:

Bug reference: 1756
Logged by: Denis Vlasenko
Email address: vda(at)ilport(dot)com(dot)ua
PostgreSQL version: 8.0.1
Operating system: Linux
Description: PQexec eats huge amounts of memory
Details:

Verbatim from http://bugs.php.net/bug.php?id=33587:

Description:
------------
Seen on php-4.3.4RC2. Since I was just testing how good
PG fares compared to Oracle, and I am not feeling any
real pain from this (IOW: not my itch to scratch),
I do not research this in depth, apart from submitting
bug report. Sorry.

Symptom: even the simplest query
$result = pg_query($db, "SELECT * FROM big_table");
eats enormous amounts of memory on server
(proportional to table size).

I think this is a problem with PostgreSQL client libs.
php's source is included for easy reference.

PHP_FUNCTION(pg_query)
{

...
pgsql_result = PQexec(pgsql, Z_STRVAL_PP(query));
if ((PGG(auto_reset_persistent) & 2) && PQstatus(pgsql) !=
CONNECTION_OK) {
PQclear(pgsql_result);
PQreset(pgsql);
pgsql_result = PQexec(pgsql, Z_STRVAL_PP(query));
}

if (pgsql_result) {
status = PQresultStatus(pgsql_result);
} else {
status = (ExecStatusType) PQstatus(pgsql);
}

switch (status) {
case PGRES_EMPTY_QUERY:
case PGRES_BAD_RESPONSE:
case PGRES_NONFATAL_ERROR:
case PGRES_FATAL_ERROR:
php_error_docref(NULL TSRMLS_CC, E_WARNING,
"Query failed: %s.", PQerrorMessage(pgsql));
PQclear(pgsql_result);
RETURN_FALSE;
break;
case PGRES_COMMAND_OK: /* successful command that did
not return rows */
default:
if (pgsql_result) {
pg_result = (pgsql_result_handle *)
emalloc(sizeof(pgsql_result_handle));
pg_result->conn = pgsql;
pg_result->result = pgsql_result;
pg_result->row = 0;
ZEND_REGISTER_RESOURCE(return_value,
pg_result, le_result);
} else {
PQclear(pgsql_result);
RETURN_FALSE;
}
break;
}
}