Hi, Nikita, On Sep 03, Nikita Malyavin wrote: > One more stack of questions: > > > > +show columns from t1; > > > +Field Type Null Key Default Extra > > > +id int(11) NO PRI NULL > > > +s timestamp(6) NO NULL > > > +e timestamp(6) NO NULL > > > +select * from information_schema.periods where table_schema = 'test'; > > > +TABLE_CATALOG TABLE_SCHEMA TABLE_NAME PERIOD > > > START_COLUMN_NAME END_COLUMN_NAME > > > +def test t2 SYSTEM_TIME row_start row_end > > > > I don't think so, they're INVISIBLE_SYSTEM. for all practical purposes they > > don't exist as columns in the table. Shouldn't be shown either. > > But don't remove this test, let's keep it to show that row_start/row_end > > are > > *not* shown here. > > And add table t3 with full standard definition of period for system_time. > > it should be shown all right. > > The columns -- I've checked -- can be accessed in SELECT, so why not > show it?
They can be accessed by SELECT, but they aren't _columns_. No other I_S table show them, SHOW CREATE doesn't show them. They're pseudo-columns, like, for example, ROWID in Oracle. > What should be the value then? An empty string? Or make it NULLable? > The period itself is also accessible in SELECT, so I suppose it should > be shown. No. If SHOW CREATE TABLE doesn't show something - this something doesn't exist as an object in the table, so information_schema.periods should not show it either. Regards, Sergei VP of MariaDB Server Engineering and secur...@mariadb.org _______________________________________________ developers mailing list -- developers@lists.mariadb.org To unsubscribe send an email to developers-le...@lists.mariadb.org
