Intro* INSERT statements could face a non-existant block when MCOL-498 feature
is enabled. writeRow() guard blocks was supposed to proactively create empty
blocks. The pre-patch logic failed when first value in the block has been
removed by DELETE and this overwrites the whole valid block with empty magics.
This patch moves proactive creation logic into allocRowId().
for extent extention.
Added a getter, moved some methods from protected into public to use
with unit tests, e.g createFile, setPreallocSpace. Added code stub in
FileOp::oid2FileName to use with UT.
Add more comments.
Changed return value for HDFS'es fallocate.
Removed unnecessary code in ColumnBufferCompressed::writeToFile
Replaced Nulls with Empties in variable names.
HWM for DML and API was being calculated using the first column in a
table instead of the smallest column. This shifts the calculation to the
correct column.
* TEXT and BLOB now have separate identifiers internally
* TEXT columns are identified as such in system catalog
* cpimport only requires hex input for BLOB, not TEXT
* DML writes for multi-block dictionary (blob) now works
* PrimProc fixed so that the first block in multi-block is read
correctly
* Performance optimisation (removed string copy into stack) for new
dictionary entries
