本文為英文版的機器翻譯版本，如內容有任何歧義或不一致之處，概以英文版為準。
aurora_stat_dml_activity
報告 Aurora PostgreSQL 叢集中資料庫上每種資料處理語言 (DML) 作業類型的累積活動。
語法
aurora_stat_dml_activity(database_oid)引數
- database_oid
-
Aurora PostgreSQL 叢集中資料庫的物件 ID (OID)。
傳回類型
SETOF 記錄
使用須知
aurora_stat_dml_activity 函數僅適用於與 PostgreSQL 引擎 11.6 及更新版本相容的 Aurora PostgreSQL 3.1 版。
在具有大量資料庫的 Aurora PostgreSQL 叢集上使用此函數，來識別哪些資料庫具有較多或較慢的 DML 活動，或兩者兼具。
aurora_stat_dml_activity 函數傳回的作業執行的次數，及 SELECT、INSERT、UPDATE 和 DELETE 作業的累積延遲 (以微秒為單位)。該報告僅包含成功的 DML 作業。
您可使用 PostgreSQL 統計數字存取函數 pg_stat_reset 來重置此統計數字。您可使用 pg_stat_get_db_stat_reset_time 函數，檢查上次重設此統計數字的時間。如需有關 PostgreSQL 統計數字存取函數的詳細資訊，請參閱 PostgreSQL 文件中的統計數字收集器
範例
下列範例顯示如何報告已連線資料庫的 DML 活動統計數字。
––Define the oid variable from connected database by using \gset=>SELECT oid, datname FROM pg_database WHERE datname=(select current_database()) \gset=>SELECT * FROM aurora_stat_dml_activity(:oid);select_count | select_latency_microsecs | insert_count | insert_latency_microsecs | update_count | update_latency_microsecs | delete_count | delete_latency_microsecs --------------+--------------------------+--------------+--------------------------+--------------+--------------------------+--------------+-------------------------- 178957 | 66684115 | 171065 | 28876649 | 519538 | 1454579206167 | 1 | 53027–– Showing the same results with expanded display on=>SELECT * FROM aurora_stat_dml_activity(:oid);-[ RECORD 1 ]------------+-------------- select_count | 178957 select_latency_microsecs | 66684115 insert_count | 171065 insert_latency_microsecs | 28876649 update_count | 519538 update_latency_microsecs | 1454579206167 delete_count | 1 delete_latency_microsecs | 53027
下列範例顯示 Aurora PostgreSQL 叢集中所有資料庫的 DML 活動統計數字。此叢集有兩個資料庫：postgres 和 mydb。以逗號分隔的清單會與 select_count、select_latency_microsecs、insert_count、insert_latency_microsecs、update_count、update_latency_microsecs、delete_count 和 delete_latency_microsecs 欄位相對應。
Aurora PostgreSQL 建立並使用一個名為 rdsadmin 的系統資料庫來支援管理作業，例如備份、還原、運作狀態檢查、複寫等等。這些 DML 作業對您的 Aurora PostgreSQL 叢集並無任何影響。
=>SELECT oid, datname, aurora_stat_dml_activity(oid) FROM pg_database;oid | datname | aurora_stat_dml_activity -------+----------------+----------------------------------------------------------------- 14006 | template0 | (,,,,,,,) 16384 | rdsadmin | (2346623,1211703821,4297518,817184554,0,0,0,0) 1 | template1 | (,,,,,,,) 14007 | postgres | (178961,66716329,171065,28876649,519538,1454579206167,1,53027) 16401 | mydb | (200246,64302436,200036,107101855,600000,83659417514,0,0)
下列範例顯示所有資料庫的 DML 活動統計數字以資料欄進行編排，提高可讀性。
SELECT db.datname, BTRIM(SPLIT_PART(db.asdmla::TEXT, ',', 1), '()') AS select_count, BTRIM(SPLIT_PART(db.asdmla::TEXT, ',', 2), '()') AS select_latency_microsecs, BTRIM(SPLIT_PART(db.asdmla::TEXT, ',', 3), '()') AS insert_count, BTRIM(SPLIT_PART(db.asdmla::TEXT, ',', 4), '()') AS insert_latency_microsecs, BTRIM(SPLIT_PART(db.asdmla::TEXT, ',', 5), '()') AS update_count, BTRIM(SPLIT_PART(db.asdmla::TEXT, ',', 6), '()') AS update_latency_microsecs, BTRIM(SPLIT_PART(db.asdmla::TEXT, ',', 7), '()') AS delete_count, BTRIM(SPLIT_PART(db.asdmla::TEXT, ',', 8), '()') AS delete_latency_microsecs FROM (SELECT datname, aurora_stat_dml_activity(oid) AS asdmla FROM pg_database ) AS db;datname | select_count | select_latency_microsecs | insert_count | insert_latency_microsecs | update_count | update_latency_microsecs | delete_count | delete_latency_microsecs ----------------+--------------+--------------------------+--------------+--------------------------+--------------+--------------------------+--------------+-------------------------- template0 | | | | | | | | rdsadmin | 4206523 | 2478812333 | 7009414 | 1338482258 | 0 | 0 | 0 | 0 template1 | | | | | | | | fault_test | 66 | 452099 | 0 | 0 | 0 | 0 | 0 | 0 db_access_test | 1 | 5982 | 0 | 0 | 0 | 0 | 0 | 0 postgres | 42035 | 95179203 | 5752 | 2678832898 | 21157 | 441883182488 | 2 | 1520 mydb | 71 | 453514 | 0 | 0 | 1 | 190 | 1 | 152
下列範例顯示了資料庫 (具 OID 16401) 之每個 DML 作業的平均累積延遲 (累積延遲除以計數)。
=>SELECT select_count, select_latency_microsecs, select_latency_microsecs/NULLIF(select_count,0) select_latency_per_exec, insert_count, insert_latency_microsecs, insert_latency_microsecs/NULLIF(insert_count,0) insert_latency_per_exec, update_count, update_latency_microsecs, update_latency_microsecs/NULLIF(update_count,0) update_latency_per_exec, delete_count, delete_latency_microsecs, delete_latency_microsecs/NULLIF(delete_count,0) delete_latency_per_exec FROM aurora_stat_dml_activity(16401);-[ RECORD 1 ]------------+------------- select_count | 451312 select_latency_microsecs | 80205857 select_latency_per_exec | 177 insert_count | 451001 insert_latency_microsecs | 123667646 insert_latency_per_exec | 274 update_count | 1353067 update_latency_microsecs | 200900695615 update_latency_per_exec | 148478 delete_count | 12 delete_latency_microsecs | 448 delete_latency_per_exec | 37
