By moving the initialization into Worker::run, all threads, including the
main thread, are properly initialized. This was not noticed before as
qc_sqlite initialized the main thread in the process initialization
callback.
The enums exposed by the connector are not intended to be used by the
users of the library. The fact that the protocol, and other, modules used
it was in violation of how the library is intended to be used.
Adding an internal mapping into MaxScale also removes some of the
dependencies that the core has on the connector.
Basically it would be trivial to report far more operations
explicitly, but for the fact that the values in qc_query_op_t
currently, quite unnecessarily, form a bitmask.
In 2.2 that is no longer the case, so other operations will be
added there.
Before this change, only db2.t2 was reported as table name for a
select like
select * from db1.t1 union select * from db2.t2
With this change, db1.t1 and db2.t2 are reported.
There are some issues still
- With recursive CTEs qc_mysqlembedded and qc_sqlite agree upon
the real columns, but disagree on the CTE related "virtual"
columns. That's largely irrelevant though.
- qc_sqlite cannot parse "SET STATEMENT var=... FOR stmt",
but it will be classified as QUERY_TYPE_GSYSVAR_WRITE.
This is not directly CTE related.
The "parser" of compare cannot handle the following:
prepare stmt1 from "
with t as (select a from t1 where b >= 'c')
select * from t2,t where t2.c=t.a;
";
That is, that a line *not* terminating the full statement (the
line 'select * from t2,t where t2.c=t.a;' above) ends with a ';'.
Thus, it needs to be changed into e.g.
prepare stmt1 from "
with t as (select a from t1 where b >= 'c')
select * from t2,t where t2.c=t.a;";
In the context of subselects and CTEs it is somewhat difficult to
make qc_sqlite and qc_mysqlembedded to agree upon in what context
a particular field is used. As that information is not used anywhere,
a usage discrepancy is for now treated as a warning.
With this change, for a statement like
SELECT t2.a FROM t1 t2;
the affected field is reported as t1.a and not as t2.a, as it
was before.
For a statement like
SELECT t.f FROM d.t;
qc_mysqlembedded will now return "d.t.f" as the affected field,
while qc_sqlite will still return "t.f" as both implementations did
before. In qc_mysqlembedded's case that is a side-effect of the
alias handling. To get qc_sqlite to return the same (which would
be good), the table names would have to be collected in a smarter
way than they are now.
The default sql mode must now be provided explicitly when the query
classifier is setup. This is in preparation for "sql_mode" becoming
a global configuration parameter of MaxScale.
That's where it belongs as it is only the mysql client protocol that
will use it. It's a bit unfortunate that the qc test program compare
now needs to include a file from a protocol module directory, but
the fact is that the query classifier implementation and the test
programs should actually be *under* the mysql client protocol module.
