This patch strips out our old version of Snappy and uses the OS version
instead. All our supported OSes have the latest version of Snappy in
their base repositories.
The end of a cpimport adds a delay which is 1 second multiplied by the
number of PMs. This in-turn is multipled up with the number of
connections/threads causing a long delay when you have several PMs.
The delay is not required as we already have a 20ms delay and we will
re-enter the recv() if there is no data and we are still connected.
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
This fix improves the performance of ExeMgr by doing the following:
* Significantly reduces the amount of time the xml configuration is
scanned
* Uses a much faster way to determine the CPU core count
* Reduces the amount of times certain allocations are executed
* Rowgroup pre-allocates vectors for 1024 rows
This improves performance for the first query of a connection and the
performance for smaller result sets. It may well improve performance in
other areas too.
It is possible for a BLOB/TEXT column to appear in a cross engine join.
This causes an ExeMgr crash later during execution. For now this patch
disable BLOB/TEXT support.
This patch allows the following syntax to change the current
autoincrement value for the table:
ALTER TABLE table_name COMMENT='autoincrement=value';
Where "value" is the new integer to be used.
