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[Oracle]如何在億級記錄表中創建索引
瀏覽:131日期:2023-11-22 09:53:11
1. 查看表的具體情況 查看是不是分區表,有多少個分區、分區字段: SQL> col table_name for a20 SQL> col column_name for a20 SQL> select a.table_name,a.partitioned,b.partition_count,c.column_name 2 from user_tables a, user_part_tables b, user_part_key_columns c 3 where a.table_name='STAT_SUBMIT_CENTER' 4 and b.table_name='STAT_SUBMIT_CENTER' 5 and c.name='STAT_SUBMIT_CENTER'; TABLE_NAME PAR PARTITION_COUNT COLUMN_NAME -------------------- --- --------------- -------------------- STAT_SUBMIT_CENTER YES 50 MSGDATE 查看已使用的每個分區的大小: SQL> select segment_name,partition_name,round(bytes/1024/1024) from user_segments where segment_name ='STAT_SUBMIT_CENTER' and bytes/1024/1024>0.25 order by 3 desc; SEGMENT_NAME PARTITION_NAME SEGMENT_NAME PARTITION_NAME ROUND(BYTES/1024/1024) -------------------------- ------------------------------ ---------------------- STAT_SUBMIT_CENTER STAT_SUBMIT_CENTER_20051101 1722 STAT_SUBMIT_CENTER STAT_SUBMIT_CENTER_20051021 1488 STAT_SUBMIT_CENTER STAT_SUBMIT_CENTER_20051111 1440 STAT_SUBMIT_CENTER STAT_SUBMIT_CENTER_20051121 1355 STAT_SUBMIT_CENTER STAT_SUBMIT_CENTER_20051221 1335 STAT_SUBMIT_CENTER STAT_SUBMIT_CENTER_20050911 1309 STAT_SUBMIT_CENTER STAT_SUBMIT_CENTER_20051211 1253 STAT_SUBMIT_CENTER STAT_SUBMIT_CENTER_20051201 1247 STAT_SUBMIT_CENTER STAT_SUBMIT_CENTER_20050921 1198 STAT_SUBMIT_CENTER STAT_SUBMIT_CENTER_20060101 1151 STAT_SUBMIT_CENTER STAT_SUBMIT_CENTER_20060111 1068 STAT_SUBMIT_CENTER STAT_SUBMIT_CENTER_20051001 1018 STAT_SUBMIT_CENTER STAT_SUBMIT_CENTER_20051011 865 STAT_SUBMIT_CENTER STAT_SUBMIT_CENTER_20060121 796 14 rows selected. 查看整個表的大小: SQL> select segment_name,sum(bytes/1024/1024) from user_segments where segment_name ='STAT_SUBMIT_CENTER' group by segment_name; SEGMENT_NAME SEGMENT_NAME SUM(BYTES/1024/1024) -------------------------------- -------------------- STAT_SUBMIT_CENTER 17234 查看表的記錄數: SQL> set timing on SQL> select count(*) from STAT_SUBMIT_CENTER; COUNT(*) ---------- 170341007 Elapsed: 00:14:18.60 查看這個表上的索引情況如下: table STAT_SUBMIT_CENTER 17234 M index IDX_SUBCEN_ADDRUSER 5155 M ADDRUSER PK_STAT_SUBMIT_CENTER 10653 M MSGDATE,ADDRUSER,MSGID然后,查看一些數據庫參數情況: SQL> show parameter work NAME TYPE VALUE NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ workarea_size_policy string AUTO SQL> show parameter pga NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ pga_aggregate_target big integer 209715200 SQL> select * from dba_temp_files; FILE_NAME ------------------------------------------------------------------------------------------------------------------------ FILE_ID TABLESPACE_NAME BYTES BLOCKS STATUS RELATIVE_FNO AUT MAXBYTES MAXBLOCKS ---------- ------------------------------ ---------- ---------- --------- ------------ --- ---------- ---------- INCREMENT_BY USER_BYTES USER_BLOCKS ------------ ---------- ----------- /bgdata/Oracle/temp01.dbf 1 TEMP 3563061248 434944 AVAILABLE 1 YES 4294967296 5242886400 3562012672 434816 2. 需要考慮的幾個方面 1)創建的索引需要幾個G的磁盤空間。 2)創建索引需要排序,使用pga_aggregate_target,要把這個值從200M加大到2G。 3)假如內存不夠,需要temp表空間,則要把temp表空間加大到8G——itpub上有一個帖子說過,15億條記錄用了34G空間。 4)在線創建,時間會比較長。討論后,停止這個表的操作,非online創建。 3. 實際操作過程 1)數據文件夠,不擴展;temp數據文件擴展: alter database tempfile '/bgdata/oracle/temp01.dbf' resize 8192m; 2)在workarea_size_policy=AUTO的情況下,改pga_aggregate_target=2048m。對于串行操作,一個session能使用的pga=MIN(5%PGA_AGGREGATE_TARGET,100MB),這樣可以使得pga用到最大的值: alter system set pga_aggregate_target=2048m; 3)因為這是一個比較長的過程,所以寫腳本讓后臺運行: nohup time createind.sh & vi createind.sh #!/bin/sh sqlplus user/passWord <
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