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bpo-32215: Fix performance regression in sqlite3 #8511

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Merged
berkerpeksag merged 1 commit into from
Sep 20, 2018
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bpo-32215: Fix performance regression in sqlite3 #8511

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2 changes: 2 additions & 0 deletions Misc/NEWS.d/next/Library/2018-07-28-12-08-53.bpo-32215.EU68SY.rst
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Original file line number Diff line number Diff line change
@@ -0,0 +1,2 @@
Fix performance regression in :mod:`sqlite3` when a DML statement appeared
in a different line than the rest of the SQL query.
8 changes: 4 additions & 4 deletions Modules/_sqlite/statement.c
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Expand Up @@ -85,10 +85,10 @@ int pysqlite_statement_create(pysqlite_Statement* self, pysqlite_Connection* con
continue;
}

self->is_dml = (PyOS_strnicmp(p, "insert ", 7) == 0)
|| (PyOS_strnicmp(p, "update ", 7) == 0)
|| (PyOS_strnicmp(p, "delete ", 7) == 0)
|| (PyOS_strnicmp(p, "replace ", 8) == 0);
self->is_dml = (PyOS_strnicmp(p, "insert", 6) == 0)
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@serhiy-storchaka serhiy-storchaka Jul 28, 2018

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Are there commands that start with "update", "delete", etc? Can a user function that starts with such prefix (for example "replacewhitespaces()") be used in this context?

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@berkerpeksag berkerpeksag Jul 28, 2018

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Can a user function that starts with such prefix (for example "replacewhitespaces()") be used in this context?

Yes, they can. The original intent of the old version was to make that check more robust and avoid cases like you've mentioned. I don't think there is a way to achieve this without relying on SQLite APIs, but then relying on newer APIs usually results seeing "I can't compile the sqlite3 module on my system" issues on the tracker :)

|| (PyOS_strnicmp(p, "update", 6) == 0)
|| (PyOS_strnicmp(p, "delete", 6) == 0)
|| (PyOS_strnicmp(p, "replace", 7) == 0);
break;
}

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