| From: | preetika tyagi <preetikatyagi(at)gmail(dot)com> |
|---|---|
| To: | pgsql-students(at)postgresql(dot)org |
| Subject: | query execution time |
| Date: | 2011-03-21 04:59:33 |
| Message-ID: | AANLkTi=FhaO5mX_YdqqsF1Yh0YNEHW8H1f0AUdpE0Fmo@mail.gmail.com |
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| Thread: | |
| Lists: | pgsql-general pgsql-students |
Hi,
I am wondering if someone can help me understand the following query
execution behavior:
I have two similar tables and table2 consists of 5000000 records.
Query: INSERT INTO table1 SELECT * FROM table2.
Execution Time: A ms.
Query: INSERT INTO table1 SELECT * FROM table2.
Execution Time: B ms.
Sometimes B >> A (B is very larger than A). Both queries are same and run
twice. What could be the reason that the same query is taking very long
sometime?
Thanks a lot!
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