Updated on 2024-09-30 GMT+08:00

PGXC_GET_TABLE_SKEWNESS

PGXC_GET_TABLE_SKEWNESS displays the data skew on tables in the current database. Only the system administrator or the preset role gs_role_read_all_stats can access this view.

Table 1 PGXC_GET_TABLE_SKEWNESS columns

Name

Type

Description

schemaname

name

Schema name of a table

tablename

name

Name of a table

totalsize

numeric

Total size of a table, in bytes

avgsize

numeric(1000,0)

Average table size (total table size divided by the number of DNs), which is the ideal size of tables distributed on each DN

maxratio

numeric(10,3)

Ratio of the maximum table size on a single DN to to avgsize

minratio

numeric(10,3)

Ratio of the minimum table size on a single DN to avgsize

skewsize

bigint

Table skew rate (the maximum table size on a single DN minus the minimum table size on a single DN)

skewratio

numeric(10,3)

Table skew rate (skewsize/avgsize)

skewstddev

numeric(1000,0)

Standard deviation of table distribution (For two tables of the same size, a larger deviation indicates a more severe skew.)