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AskSQLTeam
Ask SQLTeam Question
0 Posts |
 Posted - 2002-02-18 : 09:25:47
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| Krishnamurthy writes "We have SQL 6.5 running on WinNT. select statement on some tables with large data is slow in fetching data. I get a logical read value of about 275 and table count of 1. The server is a dedicated one and runs on 500 MHz 128 MB RAM. Will upgrading help, and is there is way to estimate the system requirement?Thanks." |
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robvolk
Most Valuable Yak
15732 Posts |
Posted - 2002-02-18 : 10:00:05
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| Upgrading definitely won't hurt, but it may not solve the problem either. You should at least add more RAM, as much as you can, but bring it up to at least 512 MB.You might clear up the problem simply by running a DBCC DBREINDEX and UPDATE STATISTICS on your tables (DBCC CHECKDB is also a good idea). This will clean up and update your indexes; if you have a clustered index on your tables it will also "defragment" them somewhat; the data will be redistributed in a more continguous manner. My guess is that your tables have had a lot of INSERT/UPDATE/DELETE activity without regular maintenance, and are fragmented enough to affect the query performance. If this clears up the problem, have a procedure in place to run these operations on a regular schedule, once a week or so should be fine (you can even make a job out of it and it can be run automatically by the SQL Executive service).Read up on these DBCC commands in Books Online, there are some specific options you should use (don't have the 6.5 BOL in front of me, I can't tell which ones they are), but you'll be able to figure it out.Edited by - robvolk on 02/18/2002 10:01:03 |
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MuadDBA
628 Posts |
Posted - 2002-02-19 : 18:00:58
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| If you have logical reads of only 275 on a single table, your query shouldn't be so slow, I wouldn't think. That means it only had to do 275 reads, which is not a lot for even a low-powered SQLServer to handle.You should probably examine the other loads being placed on the server at the same time as this query, by using SQLProfiler and Performance Monitor...perhaps there is a lot of activity you are unaware of and this is causing your problems. If so, upgrading your hardware could certainly help, but it may be unnecessary if, for example, you're getting 20 queries per minute on an un-indexed table and adding an index would drop the load on the server considerably...Look into a few more things, try Rob's suggestions, and then drop on by again....we'll be happy to help you out with more sugestions :)Joe |
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How to upgrade hardware