opt: wrap virtual computed column projections in a cast #105736
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Hold off on reviewing - looks like this regressed some query plans. I'll see if there's a way to fix that. |
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complete! 0 of 0 LGTMs obtained (waiting on @DrewKimball, @mgartner, and @msirek)
-- commits line 6 at r1:
Probably #73743.
This commit removes a TODO that was partially addressed by cockroachdb#82022. Informs cockroachdb#73743 Release note: None
This commit fixes a bug in `types.T.Identical` which caused it to return false for collated string types with a different string-representation of locales that represents the same locale logically. For example, collated string types with locales `en_US` and `en_us` would not be identical, even though these are both valid representations of the same locale. There is no release note because this has not caused any known bugs. Release note: None
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This should be ready for a look now.
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Previously, yuzefovich (Yahor Yuzefovich) wrote…
Probably #73743.
Fixed, thanks.
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Reviewed 1 of 1 files at r1, 6 of 6 files at r3, 2 of 2 files at r4, 7 of 8 files at r5, all commit messages.
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-- commits line 34 at r5:
nit: "the correct the value" --> "the correct value"
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Is the fix for #73743 coming in a separate PR?
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optbuilder wraps an assignment cast around a virtual computed column expression when writing to the table if the expression does not have the same type as the virtual column. This matches the behavior of all writes to columns of expressions that don't match the target column type. However, the same cast was not applied to the projection of the virtual column expression when reading from the table. This cast is necessary in order to produce the correct value of the column - the projection must produce the same value that would have been written to the table if the column was a stored computed column. This commit corrects optbuilder so that the cast is correctly added to the projection. Note that this commit adds a standard cast, not an assignment cast, as a temporary workaround until cockroachdb#81698 is addressed. This is because an assignment cast can fail in cases when a regular cast will not. Because we don't validate that all existing rows can successfully produce a new virtual column expression during a backfill, adding an assignment cast to the projection of the virtual column could cause future reads to error. Once cockroachdb#81698 is addressed, we can change these casts to assignment casts so that they directly match the values that would be written to the same column if it were stored. Fixes cockroachdb#91817 Informs cockroachdb#81698 Release note (bug fix): A bug has been fixed that could produce incorrect values for virtual computed columns in rare cases. The bug only presented when the virtual column expression's type did not match the type of the virtual column.
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Is the fix for #73743 coming in a separate PR?
I have no plans to fix that one at the moment. I would like to address #81698 soon, though - it can cause lots of problems.
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Previously, msirek (Mark Sirek) wrote…
nit: "the correct the value" --> "the correct value"
Done.
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TFTRs! bors r+ |
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Build succeeded: |
sql/logictest: remove assignment cast TODO
This commit removes a TODO that was partially addressed by #82022.
Informs #73743
Release note: None
sql/types: fix T.Identical
This commit fixes a bug in
types.T.Identicalwhich caused it to returnfalse for collated string types with a different string-representation
of locales that represents the same locale logically. For example,
collated string types with locales
en_USanden_uswould not beidentical, even though these are both valid representations of the same
locale.
There is no release note because this has not caused any known bugs.
Release note: None
opt: wrap virtual computed column projections in a cast
optbuilder wraps an assignment cast around a virtual computed column
expression when writing to the table if the expression does not have the
same type as the virtual column. This matches the behavior of all writes
to columns of expressions that don't match the target column type.
However, the same cast was not applied to the projection of the virtual
column expression when reading from the table. This cast is necessary in
order to produce the correct value of the column - the projection must
produce the same value that would have been written to the table if the
column was a stored computed column. This commit corrects optbuilder so
that the cast is correctly added to the projection.
Note that this commit adds a standard cast, not an assignment cast, as a
temporary workaround until #81698 is addressed. This is because an
assignment cast can fail in cases when a regular cast will not. Because
we don't validate that all existing rows can successfully produce a new
virtual column expression during a backfill, adding an assignment cast
to the projection of the virtual column could cause future reads to
error. Once #81698 is addressed, we can change these casts to assignment
casts so that they directly match the values that would be written to
the same column if it were stored.
Fixes #91817
Informs #81698
Release note (bug fix): A bug has been fixed that could produce incorrect
values for virtual computed columns in rare cases. The bug only
presented when the virtual column expression's type did not match the
type of the virtual column.