Except operation
| От | Satyajeet Seth |
|---|---|
| Тема | Except operation |
| Дата | |
| Msg-id | Pine.LNX.4.10.9912020004510.3321-100000@vibhas.cse.iitd.ernet.in обсуждение исходный текст |
| Ответ на | do queries from strings in pgplsql (Virgilio Sanz <vsanz@el-mundo.net>) |
| Список | pgsql-sql |
Hi The query: select * from webdata except select * from webdata1;takes abysmally long .How can I optimise it? The particulars are: tracedb=> \d webdata Table = webdata +----------------------------------+----------------------------------+-------+ | Field | Type | Length| +----------------------------------+----------------------------------+-------+ | tid | int4 | 4 | | itemid | int4 | 4 | | ordering | int4 | 4 | +----------------------------------+----------------------------------+-------+ tracedb=> \d webdata1 Table = webdata1 +----------------------------------+----------------------------------+-------+ | Field | Type | Length| +----------------------------------+----------------------------------+-------+ | tid | int4 | 4 | | itemid | int4 | 4 | | ordering | int4 | 4 | +----------------------------------+----------------------------------+-------+ tracedb=> select count(*) from webdata; count ----- 91155 (1 row) tracedb=> select count(*) from webdata1; count -----9550 (1 row) Regards Satya
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