An Alternative Way To Get the Table's Rowcount

,

To get the total row count in a table, we usually use the following select statement:

SELECT count(*) FROM 

This query will perform full table scan to get the row count.

You can check it by setting SET SHOWPLAN ON for SQL Server 6.5 or

SET SHOWPLAN_TEXT ON for SQL Server 7.0. So, if the table is very

big, it can take a lot of time. This is the example of simple table

creation and addition of new records into this table:

CREATE TABLE tbTest (

id int identity primary key,

Name char(10)

)

GO

DECLARE @i int

SELECT @i = 1

WHILE @i <= 10000

BEGIN

INSERT INTO tbTest VALUES (LTRIM(str(@i)))

SELECT @i = @i + 1

END

GO

There is another way to determine the total row count in a table.

You can use sysindexes system table for this purpose. There is

field ROWS in the sysindexes table. This field contains the total

row count for each table in your database. So, you can use the

following select statement instead above one:

SELECT rows FROM sysindexes

WHERE id = OBJECT_ID('table_name') AND indid < 2

There are physical read and logical read operations. A logical read

occurs if the page is currently in the cache. If the page is not

currently in the cache, a physical read is performed to read the page

into the cache. To see how many logical or physical read operations

were made, you can use SET STATISTICS IO ON command.

This is the example:

SET STATISTICS IO ON

GO

SELECT count(*) FROM tbTest

GO

SELECT rows FROM sysindexes WHERE id = OBJECT_ID('tbTest') AND indid < 2

GO

SET STATISTICS IO OFF

GO

This is the results:

-----------

10000

(1 row(s) affected)

Table 'tbTest'. Scan count 1, logical reads 32, physical reads 0, read-ahead

reads 0.

rows

-----------

10000

(1 row(s) affected)

Table 'sysindexes'. Scan count 1, logical reads 2, physical reads 0,

read-ahead reads 0.

So, you can improve the speed of the first query in several times.

This works for SQL Server 6.5 and SQL Server 7.0 as well.

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