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  1. MariaDB Server
  2. MDEV-27208

Implement 2-ary CRC32() and the CRC32C() function

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      Description

      The SQL parser defines the unary function crc32() that computes the CRC-32 of a string using the ISO 3309 polynomial that is being used by zlib and many others.

      Often, CRC is computed in pieces. To faciliate this, we introduce an optional second parameter: crc32('MariaDB') is equal to crc32(crc32('Maria','DB')).

      InnoDB files use a different polynomial, which is used by the special instructions that the Intel Nehalem microarchitecture introduced in SSE4.2. This is commonly called CRC-32C.

      It would be very convenient to introduce an SQL function crc32c() that would compute CRC-32C checksums. Then we could could define simple SQL function that would generate a logically empty InnoDB redo log corresponding to a particular checkpoint LSN. Starting with MDEV-14425 and MDEV-27199, InnoDB would refuse normal startup if the redo log file was deleted.

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              Assignee:
              marko Marko Mäkelä
              Reporter:
              marko Marko Mäkelä
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