A non version specific executable comment, such as "/*! SELECT 1; */"
is during classification handled as if it would not be a comment. That
is, the contained statement will *always* be parsed.
A version specific executable comment, such as "/*!99999 CREATE PROCEDURE
bypass BEGIN */ SELECT ... " is during classification handled as it would
be a general comment. That is, the contained statement will *never* be
parsed.
In addition, in the latter case the parse result will never be better than
QC_QUERY_PARTIALLY_PARSED. The rationale is that since the comment is version
specific, we cannot know how the server will actually interpret the statement.
This will have an impact on the masking filter and the database firewall that
now will reject statements containing _version specific_ executable comments.
Using a void return value as an integer results in undefined behavior.
apparently in this case it doesn't translate into a crash and instead only
manifests itself when all the planets align.
A statement like
SELECT ... INTO OUTFILE|DUMPFILE ...
is now classified as a QUERY_TYPE_WRITE, instead of as
QUERY_TYPE_GSYSVAR_WRITE so that it will be sent only to the
master.
SELECT...FOR UPDATE locks the rows for update, but only if
autocommit==0 or a transaction is active, so in principle even if
it were classified as READ it'd still be sent to master when it
actually matters.
However, even if autocommit==1 and/or no transaction is active, a
slave in read only mode will reject the statement if the user is
subject to the read only restriction (a user with super privileges
is not), which might be considered a server bug. By classifying the
statement as a write, it'll be sent to master and always succeed.
Only for qc_sqlite.
After a second look qc_mysqlembedded will not support dupping
the statement information. Without additional changes, simply stashing
an info object away, parsing another new GWBUF, deleting that and
then using the stashed away info object will not work; the THD object
will be corrupted. As qc_mysqlembedded is _only_ used for verifying the
sqlite-based parser this is not important anyway.
The query classifier stores information about the statement carried
by a GWBUF in the GWBUF itself. We need to be able to store that
object out side the lifetime of the GWBUF. So, we require that a
query classifier is capable of duplicating references to that object.
sqlite does not treat # as the start of a to-end-of-line
comment. It cannot trivially be treated as such because at
startup sqlite parses statements containing the #-character.
Thus, only after sqlite has been initialized can it be treated
the same way as --.
The two operations return different types of results and need to be
treated differently in order for them to be handled correctly in 2.2.
This fixes the unexpected internal state errors that happened in all 2.2
versions due to a wrong assumption made by readwritesplit. This fix is not
necessary for newer versions as the LOAD DATA LOCAL INFILE processing is
done with a simpler, and more robust, method.
Earlier only "SELECT NEXT VALUE FOR SEQ" was parsed
properly, while "SELECT PREVIOUS VALUE FOR SEQ" was not.
Now the latter statement is also parsed properly.
Fixed string truncation warnings by reducing max parameter lengths by one
where applicable. The binlogrouter filename lengths are slightly different
so using memcpy to work around the warnings is an adequate "solution"
until the root of the problem is solved.
Removed unnecessary CMake policy settings from qc_sqlite. Adding a
self-dependency on the source file of an external project has no effect
and only caused warnings to be logged.
