By my knowledge brackets of COUNT statement specify which data should be
projected and then counted
so if there is COLUMN then that column is projected (projection as
database operation) and counted
* projects all columns
and COUNT(1) projects only 1 as value for each row that is OK with WHERE
conditions
so in bad optimized database engine is COUNT(1) fastest choice
but by my short testing same problem few months ago oracle has this one
well optimized
still I use COUNT(1) as best practice because it may only do good, no
bad (in case you don't need to count distinct values of column, but all
selected rows)
hoppo
On 14.1.2010 16:08, Midana wrote:
Hello,
who knows the diference between this selects.
1 - SELECT COUNT(*) FROM TABLE
2 - SELECT COUNT(1) FROM TABLE
3 - SELECT COUNT(COLUMN) FROM TABLE
Midana Sana
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