Problem SQL
A "problem or bad SQL" means SQLs which consume more resource than commonly expected. Gelerally, almost of SQL tuners are interested in 2 stats. One is Number of block buffer access and the second is Disk I/O(means Physical I/O requiring much time) Generally, SQLs excessively using system resources result in large amount of block buffer accesses and disk reads(Physical I/O). SQL requiring large amount of block buffer access or physical I/O also requires much CPU time and disk I/O time and the response time become longer than expected. For my experience, Almost of such SQLs can be tuned to consume only 1/10 ~ 1/1000 of original resource and result in quick response. Thanks.

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이름 : nicklee 제목 : Problem SQL Hi There seems to be a lot of references to 'problem' or 'bad' SQL in your brochures/website in terms of SQL monitor.... just wondering how you actually know what 'bad' SQL is from SQL monitor.... I know it concerns stats (buffer gets, executions, etc.) but I don't know which ones exactly. Any help would be greatly appreciated. Thanks.