EM scaleability project has two parts: phase1 and phase2.
This is phase1 that brings EM index to speed up(from O(n) down
to the speed of boost::unordered_map) EM lookups looking for
<dbroot, oid, partition> tuple to turn it into LBID,
e.g. most bulk insertion meta info operations.
The basis is boost::shared_managed_object where EMIndex is
stored. Whilst it is not debug-friendly it allows to put a
nested structs into shmem. EMIndex has 3 tiers. Top down description:
vector of dbroots, map of oids to partition vectors, partition
vectors that have EM indices.
Separate EM methods now queries index before they do EM run.
EMIndex has a separate shmem file with the fixed id
MCS-shm-00060001.
1) Instead of making dbrm calls to writeVBEntry() per block,
we make these calls per batch. This can have non-trivial
reductions in the overhead of these calls if the batch size
is large.
2) In dmlproc, do not deserialize the whole insertpackage, which
consists of the complete record set per column, which would be
wasteful as we only need some metadata fields from insertpackage
here. This is only done for batch inserts at the moment, this
should also be applied to single inserts.
