[tarantool-patches] Re: [PATCH v2 0/5] sql: do not use OP_Delete+OP_Insert for UPDATES
kyukhin at tarantool.org
Thu Jan 10 15:30:51 MSK 2019
On 29 Dec 13:48, Kirill Shcherbatov wrote:
> Introduced a new OP_Update opcode making Tarantool native Update
> In case of UPDATE or REPLACE we can't use new OP_Update as it
> has a complex SQL-specific semantics:
> CREATE TABLE tj (s1 INT PRIMARY KEY, s2 INT);
> INSERT INTO tj VALUES (1, 3),(2, 4),(3,5);
> CREATE UNIQUE INDEX i ON tj (s2);
> SELECT * FROM tj;
> [1, 3], [2, 4], [3, 5]
> UPDATE OR REPLACE tj SET s2 = s2 + 1;
> SELECT * FROM tj;
> [1, 4], [3, 6]
> I.e. [1, 3] tuple is updated as [1, 4] and have replaced tuple
> [2, 4]. This logic is implemented as preventive tuples deletion
> by all corresponding indexes in SQL.
> The other significant change is forbidden primary key update.
> It was possible to deal with it the same way like with or
> REPLACE specifier but we need an atomic UPDATE step for #3691
> ticket to support "or IGNORE/or ABORT/or FAIL" specifiers.
> Reworked tests to make testing avoiding primary key UPDATE where
> Fixed bug in VDBE - sometimes temporal tuples in memory allocated
> with sql_vdbe_mem_alloc_region were stored in Mem variable having
> invalid flags set.
> Changes in version 2:
> - Reworked part of code to close tikets #3035, #3918: reused
> a new routine mpstream_encode_vdbe_mem to encode tuples on
> region everywhere on Vdbe execution: got rid of routines
> sqlite3VdbeMsgpackRecordLen and sqlite3VdbeMsgpackRecordPut
> that became useless.
> - Fixed few spell mistakes in comments and commit messages
> - Minor code changes: better mpstream methods names, changed
> OP_IdxUpdate to OP_Update name.
> Branch: http://github.com/tarantool/tarantool/tree/kshch/gh-3850-op-update
> Issue: https://github.com/tarantool/tarantool/issues/3850
I've checked your patch set into 2.1 branch.
Regards, Kirill Yukhin
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