Stealing from a Tips book or white paper. SELECT * is not always a bad thing, but it’s a good idea to only move the data you really need to move and only when you really need it, in order to avoid network, disk, and memory contention on your server.
For small sets of data that are infrequently updated such as lookup values, build a method of caching them in memory on your application server rather than constantly querying them in the database. *--**- this is a big one in that every DB has the same problem. A function on columns in the WHERE clause or JOIN criteria means that SQL Server can’t use indexes appropriately and will lead to table scans and slow performance. Avoid using a column in a clustered index that has values that are frequently updated. You do not have to make the primary key the clustered index. This is default behavior but can be directly controlled. Clustered indexes work well on columns that are used a lot for ‘range’ WHERE clauses such as BETWEEN and LIKE, where it is frequently used in ORDER BY clauses or in GROUP BY clauses. If you join to a Date|Time table adding that dtmAdded column to the primary key is very helpful and if you filter on that column it will greatly help your throughput. Only create non-clustered indexes on tables when you know they’ll be used through testing. You can seriously hurt performance by creating too many indexes on a table. While it is possible to over-normalize a database, under-normalization is much more prevalent. This leads to repetition of data, inefficient storage, and poor performance. Data normalization is a performance tuning technique as well as a storage mechanism. All from Red Gate. Stephen Russell Sr. Analyst Ring Container Technology Oakland TN 901.246-0159 cell --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html --- _______________________________________________ Post Messages to: [email protected] Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/cajidmyleu-m8t1wiczfgz0erqzsj9w9gnorf+yn0vx6zqj-...@mail.gmail.com ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
