dict_col_t Struct Reference

#include <dict0mem.h>

Data Fields
unsigned	ind:10
unsigned	ord_part:1
unsigned	max_prefix:12
unsigned	prtype:32
unsigned	mtype:8
unsigned	len:16
unsigned	mbminmaxlen:5

Detailed Description

Data structure for a column in a table

Field Documentation

unsigned dict_col_t::ind

table column position (starting from 0)

unsigned dict_col_t::len

length; for MySQL data this is field->pack_length(), except that for a >= 5.0.3 type true VARCHAR this is the maximum byte length of the string data (in addition to the string, MySQL uses 1 or 2 bytes to store the string length)

unsigned dict_col_t::max_prefix

maximum index prefix length on this column. Our current max limit is 3072 for Barracuda table

unsigned dict_col_t::mbminmaxlen

minimum and maximum length of a character, in bytes; DATA_MBMINMAXLEN(mbminlen,mbmaxlen); mbminlen=DATA_MBMINLEN(mbminmaxlen); mbmaxlen=DATA_MBMINLEN(mbminmaxlen)

unsigned dict_col_t::mtype

main data type

unsigned dict_col_t::ord_part

nonzero if this column appears in the ordering fields of an index

unsigned dict_col_t::prtype

The following are copied from dtype_t,

so that all bit-fields can be packed tightly. precise type; MySQL data type, charset code, flags to indicate nullability, signedness, whether this is a binary string, whether this is a true VARCHAR where MySQL uses 2 bytes to store the length

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The documentation for this struct was generated from the following file:

• include/dict0mem.h