TAP_SCHEMA Set of tables listing and describing the schemas, tables and columns published in this TAP service. TAP_SCHEMA.schemasList of schemas published in this TAP service. schema_name schema name, possibly qualified VARCHAR indexed primary description brief description of schema VARCHAR utype UTYPE if schema corresponds to a data model VARCHAR TAP_SCHEMA.tablesList of tables published in this TAP service. schema_name the schema name from TAP_SCHEMA.schemas VARCHAR indexed primary table_name table name as it should be used in queries VARCHAR indexed primary table_type one of: table, view VARCHAR description brief description of table VARCHAR utype UTYPE if table corresponds to a data model VARCHAR TAP_SCHEMA.columnsList of columns of all tables listed in TAP_SCHEMA.TABLES and published in this TAP service. table_name table name from TAP_SCHEMA.tables VARCHAR indexed primary column_name column name VARCHAR indexed primary description brief description of column VARCHAR unit unit in VO standard format VARCHAR ucd UCD of column if any VARCHAR utype UTYPE of column if any VARCHAR datatype ADQL datatype as in section 2.5 VARCHAR size length of variable length datatypes INTEGER principal a principal column; 1 means true, 0 means false INTEGER indexed an indexed column; 1 means true, 0 means false INTEGER std a standard column; 1 means true, 0 means false INTEGER TAP_SCHEMA.keysList all foreign keys but provides just the tables linked by the foreign key. To know which columns of these tables are linked, see in TAP_SCHEMA.key_columns using the key_id. key_id unique key identifier VARCHAR indexed primary from_table fully qualified table name VARCHAR target_table fully qualified table name VARCHAR description description of this key VARCHAR utype utype of this key VARCHAR TAP_SCHEMA.key_columnsList all foreign keys but provides just the columns linked by the foreign key. To know the table of these columns, see in TAP_SCHEMA.keys using the key_id. key_id unique key identifier VARCHAR indexed primary from_column key column name in the from_table VARCHAR target_column key column name in the target_table VARCHAR