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Meta functions Meta Table and database metadata function reference documentation.

These functions provide table information including column details and metadata such as commit lag parameters. These functions are particularly useful for checking if tables contain a designated timestamp column.

table_columns

table_columns('tableName') returns the schema of a table

Arguments:

  • tableName is the name of an existing table as a string

Return value:

Returns a table with the following columns:

  • column - name of the available columns in the table
  • type - type of the column
  • indexed - if indexing is applied to this column
  • indexBlockCapacity - how many row IDs to store in a single storage block on disk
  • symbolCached - whether or not this symbol column is cached
  • symbolCapacity - how many distinct values this column of symbol type is expected to have
  • designated - if this is set as the designated timestamp column for this table

For more details on the meaning and use of these values, see the CREATE TABLE documentation.

Examples:


1. table_columns('my_table')

column type indexed indexBlockCapacity symbolCached symbolCapacity designated
symb SYMBOL true 1048576 false 256 false
price DOUBLE false 0 false 0 false
ts TIMESTAMP false 0 false 0 true
s STRING false 0 false 0 false

1. SELECT column, type, designated FROM table_columns('my_table') WHERE designated

column type designated
ts TIMESTAMP true

1. SELECT type, count() FROM table_columns('my_table');

type count
SYMBOL 1
DOUBLE 1
TIMESTAMP 1
STRING 1

tables

tables() returns all tables in the database including table metadata.

Arguments:

  • tables() does not require arguments.

Return value:

Returns a table.

Examples:


1. tables();

id name designatedTimestamp partitionBy maxUncommittedRows commitLag
1 my_table ts DAY 500000 300000000
2 device_data null NONE 10000 30000000

1. tables() ORDER BY name DESC;

id name designatedTimestamp partitionBy maxUncommittedRows commitLag
2 device_data null NONE 10000 30000000
1 my_table ts DAY 500000 300000000

1. tables() WHERE partitionBy = 'DAY'

id name designatedTimestamp partitionBy maxUncommittedRows commitLag
1 my_table ts DAY 500000 300000000