Gagan Goel 13264feb7d MCOL-4320/4364/4370 Fix multibyte processing for LDI/Insert...Select ...

For CHAR/VARCHAR/TEXT fields, the buffer size of a field represents
the field size in bytes, which can be bigger than the field size in
number of characters, for multi-byte character sets such as utf8,
utf8mb4 etc. The buffer also contains a byte length prefix which can be
up to 65532 bytes for a VARCHAR field, and much higher for a TEXT
field (we process a maximum byte length for a TEXT field which fits in
4 bytes, which is 2^32 - 1 = 4GB!).

There is also special processing for a TEXT field defined with a default
length like so:
  CREATE TABLE cs1 (a TEXT CHARACTER SET utf8)
Here, the byte length is a fixed 65535, irrespective of the character
set used. This is different from a case such as:
  CREATE TABLE cs1 (a TEXT(65535) CHARACTER SET utf8), where the byte length
for the field will be 65535*3.

2020-10-26 17:51:24 +00:00

14 KiB

Raw Blame History

View Raw