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;
        }
}