Topic: Performance & Tuning >> count(1) versus count(*)
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| Title: count(1) versus count(*) |
| tuslerb |
Posted: Feb 15, 2003 12:34:00 AM |
Total Post: 1
Joined: Jan, 2003
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Hi Guys,
Is there any performance issues when running a select count(1) instead of select count(*)?
Thanks,
Amy
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 Sabari Nath |
| Posted: Feb 15, 2003 12:38:00 AM |  |
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Total Post: 16
Joined: Jan, 2003
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Hi Amy,
I think count(*) will do a full table scan irrespective of the indexes present on
the table and Count(1) will only scan the indexspace provided the column1 is indexed and should be faster since less bytes will be read.
Vasu.
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| uci_001 |
| Posted: Feb 15, 2003 12:40:00 AM | |
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Total Post: 1
Joined: Jan, 2003
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I believe count(1) or count(rowid) should be faster than count(*).
Count(*) will use all the columns and might degrade the performance.
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