Updated on 2022-08-16 GMT+08:00

PGXC_GET_TABLE_SKEWNESS

PGXC_GET_TABLE_SKEWNESS displays the data skew on tables in the current database.

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(4,3)

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

minratio

numeric(4,3)

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

skewsize

bigint

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

skewratio

numeric(4,3)

Table skew rate (skew size divided by total table size)

skewstddev

numeric(1000,0)

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