如何在pgstatspack中删除超过15天的快照？

Question

这就是delete.sh的样子：

#!/bin/bash

#db call to get database name

PSQL="psql -q"

pushd `dirname $0`

for dbname in `$PSQL -t -f "../sql/db_name.sql"`
do
        echo "Results for database ${dbname}"
        $PSQL -d "${dbname}" -c "select pgstatspack_delete_snap ();"
        echo ""
        echo ""
done
popd

在哪里指定应删除快照的天数？

Answer 1

http://pgfoundry.org/frs/?group_id=1000375 pgstatspack_version_2.3.1.tar.gz有pgstatspack\sql\pgstatspack_delete_old_stats.sql：

CREATE OR REPLACE FUNCTION pgstatspack_delete_snap () returns varchar(512) AS $$
DECLARE
  old_snap_time TIMESTAMP;
  old_snap_id BIGINT;
  message VARCHAR(512);
BEGIN
  SELECT current_timestamp - interval '30 days' INTO old_snap_time;

  SELECT max(snapid) INTO old_snap_id FROM pgstatspack_snap WHERE ts < old_snap_time;

  SELECT 'Deleted '||count(snapid)||' snapshots older than '||old_snap_time
  INTO message 
  FROM pgstatspack_snap 
  WHERE snapid <= old_snap_id;

  DELETE FROM pgstatspack_snap WHERE snapid <= old_snap_id;

  DELETE FROM pgstatspack_database WHERE snapid <= old_snap_id;

  DELETE FROM pgstatspack_tables WHERE snapid <= old_snap_id;

  DELETE FROM pgstatspack_indexes WHERE snapid <= old_snap_id;

  DELETE FROM pgstatspack_sequences WHERE snapid <= old_snap_id;

  DELETE FROM pgstatspack_settings WHERE snapid <= old_snap_id;

  DELETE FROM pgstatspack_statements WHERE snapid <= old_snap_id;

  DELETE FROM pgstatspack_bgwriter WHERE snapid <= old_snap_id;

  RETURN message;
END;
$$ LANGUAGE plpgsql;

所以只需创建你的功能：

CREATE OR REPLACE FUNCTION pgstatspack_delete_snap (_d interval default '30 days') returns varchar(512) AS $$
DECLARE
  old_snap_time TIMESTAMP;
  old_snap_id BIGINT;
  message VARCHAR(512);
BEGIN
  SELECT current_timestamp - _d INTO old_snap_time;

  SELECT max(snapid) INTO old_snap_id FROM pgstatspack_snap WHERE ts < old_snap_time;

  SELECT 'Deleted '||count(snapid)||' snapshots older than '||old_snap_time
  INTO message 
  FROM pgstatspack_snap 
  WHERE snapid <= old_snap_id;

  DELETE FROM pgstatspack_snap WHERE snapid <= old_snap_id;

  DELETE FROM pgstatspack_database WHERE snapid <= old_snap_id;

  DELETE FROM pgstatspack_tables WHERE snapid <= old_snap_id;

  DELETE FROM pgstatspack_indexes WHERE snapid <= old_snap_id;

  DELETE FROM pgstatspack_sequences WHERE snapid <= old_snap_id;

  DELETE FROM pgstatspack_settings WHERE snapid <= old_snap_id;

  DELETE FROM pgstatspack_statements WHERE snapid <= old_snap_id;

  DELETE FROM pgstatspack_bgwriter WHERE snapid <= old_snap_id;

  RETURN message;
END;
$$ LANGUAGE plpgsql;

并称之为：

$PSQL -d "${dbname}" -c "select pgstatspack_delete_snap ('15 days');"