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Hi, I’m not sure this is the right place to ask my
question, so please if it is not let me know where I can get an answer from. I’m using postgresql 8.4 on Linux machine with 1.5 GB
RAM, and I’m issuing an update query with a where clause that updates
approximately 100 000 rows in a table containing approximately 3 200 000 rows. The update query is very simple: UPDATE TABLE1 SET FIELD1 =
FIELD1 WHERE FIELD2 < 0.83 (the where clause is used to limit the affected
rows to ~ 100 000, and the “SET FIELD1 = FIELD1” is only on purpose
to keep the data of the table unchanged). Actually this query is inside a function and this function
is called from a .sh file (the function is called 100 times with a vacuum
analyze after each call for the table). So the average execution time of the function is around 2.5
mins, meaning that the update query (+ the vacuum) takes 2.5 mins to execute.
So is this a normal behavior? (The same function in oracle with the same
environment (with our vacuum obviously) is executed in 11 second). Note that no index is created on FIELD2 (neither in
postgresql nor in oracle) Thanks for your help. |
