PostgreSQL

/*

** Zabbix

** Copyright 2001-2024 Zabbix SIA

**

** Licensed under the Apache License, Version 2.0 (the "License");

** you may not use this file except in compliance with the License.

** You may obtain a copy of the License at

**

**     http://www.apache.org/licenses/LICENSE-2.0

**

** Unless required by applicable law or agreed to in writing, software

** distributed under the License is distributed on an "AS IS" BASIS,

** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

** See the License for the specific language governing permissions and

** limitations under the License.

**/

​

package plugin

​

import (

    "context"

    "errors"

    "fmt"

​

    "github.com/jackc/pgx/v4"

    "golang.zabbix.com/sdk/zbxerr"

)

​

const pgVersionWithChecksum = 120000

​

// dbStatHandler executes select from pg_catalog.pg_stat_database

// command for each database and returns JSON if all is OK or nil otherwise.

func dbStatHandler(ctx context.Context, conn PostgresClient,

    key string, _ map[string]string, _ ...string) (interface{}, error) {

    var statJSON, query string

​

    switch key {

    case keyDBStatSum:

        query = `

  SELECT row_to_json (T)

    FROM  (

      SELECT

        sum(numbackends) as numbackends

      , sum(xact_commit) as xact_commit

      , sum(xact_rollback) as xact_rollback

      , sum(blks_read) as blks_read

      , sum(blks_hit) as blks_hit

      , sum(tup_returned) as tup_returned

      , sum(tup_fetched) as tup_fetched

      , sum(tup_inserted) as tup_inserted

      , sum(tup_updated) as tup_updated

      , sum(tup_deleted) as tup_deleted

      , sum(conflicts) as conflicts

      , sum(temp_files) as temp_files

      , sum(temp_bytes) as temp_bytes

      , sum(deadlocks) as deadlocks

      , %s as checksum_failures

      , sum(blk_read_time) as blk_read_time

      , sum(blk_write_time) as blk_write_time

      FROM pg_catalog.pg_stat_database

    ) T ;`

        if conn.PostgresVersion() >= pgVersionWithChecksum {

            query = fmt.Sprintf(query, "sum(COALESCE(checksum_failures, 0))")

        } else {

            query = fmt.Sprintf(query, "null")

        }

​

    case keyDBStat:

        query = `

  SELECT json_object_agg(coalesce (datname,'null'), row_to_json(T))

    FROM  (

      SELECT

        datname

      , numbackends as numbackends

      , xact_commit as xact_commit

      , xact_rollback as xact_rollback

      , blks_read as blks_read

      , blks_hit as blks_hit

      , tup_returned as tup_returned

      , tup_fetched as tup_fetched

      , tup_inserted as tup_inserted

      , tup_updated as tup_updated

      , tup_deleted as tup_deleted

      , conflicts as conflicts

      , temp_files as temp_files

      , temp_bytes as temp_bytes

      , deadlocks as deadlocks

      , %s as checksum_failures

      , blk_read_time as blk_read_time

      , blk_write_time as blk_write_time

      FROM pg_catalog.pg_stat_database