Purge tables in chunks to workaround galera limits #24
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jsuchome
reviewed
Sep 26, 2018
psql2mysql/__init__.py
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| # DELETE ... LIMIT is MySQL specific and there is no way to | ||
| # express it in SQLalchemy other than using a raw query. | ||
| res = self.connection.execute( | ||
| 'DELETE FROM `%s` LIMIT 10000' % table.name |
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Why 10000? Isn't there a chance that user has it set to lower number by some config option?
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Actually the plan was to mark this WIP and adapt it to use the same chunksize as for the chunked writing passed in via parameter in (see #25 ).
Galera has limits around how many rows can be touched in single transaction. This is also affects DELETE operations. So we need to limit the deletes to a certain number of rows.
jsuchome
approved these changes
Oct 8, 2018
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Galera has limits around how many rows can be touched in single
transaction. This is also affects DELETE operations. So we need to limit
the deletes to a certain number of rows.