Introduce the sstable/colblk package for columnar block primitives, and add
a first primitive for storing bitmaps.
The Bitmap uses 1+1/64 physical bits per logical bit. Bits are organized into
64-bit words, allowing constant-time access of an individual bit. Additionally,
after the bitmap a summary bitmap consisting of 1 bit per 64-bit word of the
bitmap provides faster lookup of preceding or successive set bits. This will be
used by a bitmap indicating when a key prefix changes to quickly find the next
key within a block with a new prefix.
cockroach-teamcity
commented
3 days ago 
Introduce the sstable/colblk package for columnar block primitives, and add a first primitive for storing bitmaps.
The Bitmap uses 1+1/64 physical bits per logical bit. Bits are organized into 64-bit words, allowing constant-time access of an individual bit. Additionally, after the bitmap a summary bitmap consisting of 1 bit per 64-bit word of the bitmap provides faster lookup of preceding or successive set bits. This will be used by a bitmap indicating when a key prefix changes to quickly find the next key within a block with a new prefix.