PGXC_GET_TABLE_SKEWNESS¶
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.) |