In the joblist code, in addition to sending the lbid of the SCAN
column, we also send the corresponding lbid of the AUX column to PrimProc.
In the primitives processor code in PrimProc, we load the AUX column
block (8192 rows since the AUX column is implemented as a 1-byte
UNSIGNED TINYINT) into memory and then pass it down to the low-level
scanning (vectorized scanning as applicable) routine to build a non-Empty
mask for the block being processed to filter out DELETED rows based on
comparison of the AUX block row to the empty magic value for the AUX column.
The idea is relatively simple - encode prefixes of collated strings as
integers and use them to compute extents' ranges. Then we can eliminate
extents with strings.
The actual patch does have all the code there but miss one important
step: we do not keep collation index, we keep charset index. Because of
this, some of the tests in the bugfix suite fail and thus main
functionality is turned off.
The reason of this patch to be put into PR at all is that it contains
changes that made CHAR/VARCHAR columns unsigned. This change is needed in
vectorization work.
column width
RTSCommand was modified to use a fabric that produces CC class based on column width
NB this patch doesn't affect PseudoCC that also leverages ColumnCommand
This patch:
1. Removes the option to declare uncompressed columns (set columnstore_compression_type = 0).
2. Ignores [COMMENT '[compression=0] option at table or column level (no error messages, just disregard).
3. Removes the option to set more than 2 extents per file (ExtentsPreSegmentFile).
4. Updates rebuildEM tool to support up to 10 dictionary extent per dictionary segment file.
5. Adds check for `DBRootStorageType` for rebuildEM tool.
6. Renamed rebuildEM to mcsRebuildEM.
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
