[MySQL] Change: faster retrieval of schema #1540
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Because `information_schema.tables` and `information_schema.columns` do not have indexes on them, when they get large, joining them becomes painful. We have a database with over 10k tables and more than 200k columns. The old query takes forever. The new query do not look at `information_schema.tables` at all. This works if your `information_schema.columns` table is in good shape in terms of data integrity (and it should be). Tested on MySQL 5.5, 5.6(Percona), 5.7(Percona). The schema has not changed since then.
arikfr
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Merged. Thanks! |
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Mar 1, 2019
[MySQL] Change: faster retrieval of schema
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Because
information_schema.tablesandinformation_schema.columnsdo not have indexes on them, when they get large, joining them becomes painful. We have a database with over 10k tables and more than 200k columns. The old query takes forever.The new query do not look at
information_schema.tablesat all. This works if yourinformation_schema.columnstable is in good shape in terms of data integrity (and it should be).Tested on MySQL 5.5, 5.6(Percona), 5.7(Percona). The schema has not changed since then.