statistics_indexes
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statistics_indexes [2017/10/10 14:01] markmeteenk |
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| **Clustered index** | **Clustered index** | ||
| - | A clustered index means that data in a table is stored sorted by the fields in the index, so the query optimizer can find data as fast as possible. There can only be one clustered index. | + | A clustered index means that data in a table is stored sorted by the fields in the index, so the query optimizer can find data as fast as possible. There can only be one clustered index. If a primary key exists in a table, that will be the clustered index. |
| **Non-clustered index** | **Non-clustered index** | ||
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| Keeping the indices up-to-date can be done by means of REORGANIZE or REBUILD. The REORGANIZE option tries to find how much the data changed in a table (relatively) and will update the index if needed. The REBUILD option is the same as dropping the index and creating it again. | Keeping the indices up-to-date can be done by means of REORGANIZE or REBUILD. The REORGANIZE option tries to find how much the data changed in a table (relatively) and will update the index if needed. The REBUILD option is the same as dropping the index and creating it again. | ||
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| ===== Statistics vs indexes ===== | ===== Statistics vs indexes ===== | ||
statistics_indexes.txt ยท Last modified: 2017/10/10 14:17 by markmeteenk
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