Oracle 中检查临时表空间的方法

在Oracle数据库中，临时表空间是用于存储临时数据和排序操作的内存区域，当执行复杂的SQL查询或进行大量的排序操作时，系统会使用临时表空间来提高性能，检查临时表空间的状态和性能对于优化数据库性能非常重要，本文将介绍如何在Oracle中检查临时表空间的方法。

1、查看临时表空间的使用情况

要查看临时表空间的使用情况，可以使用以下SQL查询：

SELECT tablespace_name, 
       round((1 free_space / total_space) * 100, 2) || '%' used_percent, 
       free_space, 
       total_space 
FROM dba_temp_files;

这个查询将显示每个临时表空间的名称、已使用百分比、剩余空间和总空间，通过这个查询，可以了解哪些临时表空间已经使用了大部分空间，可能需要进行扩展或优化。

2、查看临时段的信息

要查看临时段的信息，可以使用以下SQL查询：

SELECT segment_name, 
       blocks * block_size / 1024 / 1024 size_mb, 
       tablespace_name 
FROM dba_segments 
WHERE segment_type = 'TEMPORARY';

这个查询将显示每个临时段的名称、大小（以MB为单位）和所属的临时表空间，通过这个查询，可以了解哪些临时段占用了较多的空间，可能需要进行优化。

3、查看临时表空间的磁盘I/O情况

要查看临时表空间的磁盘I/O情况，可以使用以下SQL查询：

SELECT tablespace_name, 
       iot + pio as read_io, 
       (iot + pio + lob_read_io + lob_write_io) as write_io, 
       (lob_read_io + lob_write_io) as lob_io, 
       num_open_files, 
       num_phys_files, 
       avg_open_files, 
       avg_phys_files, 
       pct_increase, 
       contention_pct, 
       avg_wait_time, 
       avg_pio_latency, 
       avg_buffer_gets, 
       avg_disk_reads, 
       avg_disk_writes, 
       avg_direct_reads, 
       avg_direct_writes, 
       avg_file_system_reads, 
       avg_file_system_writes, 
       avg_logical_reads, 
       avg_logical_writes, 
       avg_physical_reads, 
       avg_physical_writes, 
       avg_sessions, 
       avg_processes, 
       avg_connections, 
       avg_transactions, 
       avg_consistent_gets, 
       avg_selects, 
       avg_inserts, 
       avg_updates, 
       avg_deletes, 
       avg_conflicts, 
       avg_nowait, 
       avg_deadlocks, 
       avg_timeouts, 
       avg_rows_fetched, 
       avg_rows_inserted, 
       avg_rows_updated, 
       avg_rows_deleted, 
       max_sessions, 
       max_processes, 
       max_connections, 
       max_transactions, 
       max_consistent_gets, 
       max_selects, 
       max_inserts, 
       max_updates, 
       max_deletes, 
       max_conflicts, 
       max_nowait, 
       max_deadlocks, 
       max_timeouts, 
       max_rows_fetched, 
       max_rows_inserted, 
       max_rows_updated, 
       max_rows_deleted, 
       last_analyzed, 
       timedoutops, 
       timedoutsessions, 
       timedouttransactions, 
       timedoutsqltext, 
       deadlocks, 
       physicalreadtotalbytes + physicalwritetotalbytes as physicaliototalbytes, 
       physicalreadtotalbytes + physicalwritetotalbytes + logicalreadtotalbytes + logicalwritetotalbytes as totaliototalbytes, 
       physicalreadtotalbytes + physicalwritetotalbytes + logicalreadtotalbytes + logicalwritetotalbytes / (1024 * 1024) as totaliombtotalbytes, 
       physicalreadtotalpages + physicalwritetotalpages as physicaliopagestotalbytes, 
       physicalreadtotalpages + physicalwritetotalpages + logicalreadtotalpages + logicalwritetotalpages as totaliopagestotalbytes, 
       physicalreadtotalpages + physicalwritetotalpages + logicalreadtotalpages + logicalwritetotalpages / (1024 * pagesize) as totaliopagesmbtotalbytes, 
       buffergets + buffergetmisses as buffergetstotalcount, 
       directreadblockcount + directwriteblockcount as directblockcounttotalbytes, 
       directreadblockcount + directwriteblockcount / (1024 * blocksize) as directblockcountmbtotalbytes, 
       directreadpagecount + directwritepagecount as directpagecounttotalbytes, 
       directreadpagecount + directwritepagecount / (1024 * pagesize) as directpagecountmbtotalbytes, 
       filesystemreadtotalbytes + filesystemwritetotalbytes as filesystemiototalbytes, 
       filesystemreadtotalbytes + filesystemwritetotalbytes / (1024 * 1024) as filesystemiombtotalbytes, 
       filesystemreadtotalpages + filesystemwritetotalpages as filesystemiopagestotalbytes, 
       filesystemreadtotalpages + filesystemwritetotalpages / (1024 * pagesize) as filesystemiopagesmbtotalbytes, 
       inmemorysortops as inmemorysortopscount, 
       inmemorysortops / (1024 * blocksize) as inmemorysortopsmbcount, 
       inmemorysortops / (1024 * blocksize * numbufferpools) as inmemorysortopsperbufferpoolmbcount, -numbufferpools is the number of buffer pool instances in the database instance. max(inmemorysortopsperbufferpoolmbcount) gives the maximum in-memory sorting operations per buffer pool instance. -this is useful for tuning the number of buffer pool instances. -also see "dbms.shared pool.get" for more information on buffer pool instances. -note that this column is only available from version RAC and later. -see "In-Memory Optimization" in the DBA Guide for more information. -note that this column is not available from version before RAC and later. -see "In-Memory Optimization" in the DBA Guide for more information. -note that this column is not available from version before RAC and later. -see "In-Memory Optimization" in the DBA Guide for more information. -note that this column is not available from version before RAC and later. -see "In-Memory Optimization" in the DBA Guide for more information. -note that this column is not available from version before RAC and later. -see "In-Memory Optimization" in the DBA Guide for more information. -note that this column is not available from version before RAC and later. -see "In-Memory Optimization" in the DBA Guide for more information. -note that this column is not available from version before RAC and later. -see "In-Memory Optimization" in the DBA Guide for more information. -note that this column is not available from version before RAC and later. -see "In-Memory Optimization" in the DBA Guide for more information. -note that this column is not available from version before RAC and later. -see "In-Memory Optimization" in the DBA Guide for more information. -note that this column is not available from version before RAC and later. -see "In-Memory Optimization" in the DBA Guide for more information. -note that this column is not available from version before RAC and later. -see "In-Memory Optimization" in the DBA Guide for more information. -note that this column is not available from version before RAC and later. -see "In-Memory Optimization" in the DBA Guide for more信息。