ExeMgr uses ResourceManager to count memory usage. If a usage exceeded
error occurs the counting wasn't reset and subsequent usage attempts in
the same ExeMgr thread would error.
This patch moves the in-class accounting for GroupConcat and others so
that it happens before the error is detected. The memory usage counter
is then decremented correctly on the class destructor.
pDictionaryScan won't work for BLOB/TEXT since it requires searching the
data file and rebuilding the token from matches. The tokens can't be
rebuild correctly due the bits in the token used for block counts. This
patch forces the use of pDictionaryStep instead for WHERE conditions.
In addition this patch adds support for TEXT/BLOB in various parts of
the job step processing. This fixes things like error 202 during an
UPDATE with a join condition on TEXT/BLOB columns.
This does the following:
* Switch resource manager to a singleton which reduces the amount of
times the XML data is scanned and objects allocated.
* Make the I_S tables use the FE implementation of the system catalog
* Make the I_S.columnstore_columns table use the RID list cache
* Make the extentmap pre-allocate a vector instead of many small allocs
