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