Sorry if vague, trying to track down recent website slowdown reasons, and query monitor shows me this as a DATABASE ERROR consistently for two particular transients being added:
Following the stacktrace seems to be a dead end, why is this throwing an error?
The line that triggers it is from my custom plugin setting a standard html-filled transient (10,000-20,000 chars), which has worked fine:
set_transient( $transient_name, $html, $transient_seconds ); By the way, running SHOW FULL COLUMNS FROM wp_options works fine in phpmyadmin
I also checked wp_options and saw the timeouts for these particular transients stored, but not the transient/values itself.
Any ideas?
Thanks!

SHOW FULL COLUMNS tableshould not generate errors. WordPress uses it to capture a description of the table, not the contents of the table. The datatype ofwp_options.option_valueisLONGTEXT, so a 20k transient value is no problem at all: it can handle up to 4g. Is there some other query before thisSHOW FULL COLUMNSquery showing trouble? Please edit your question to tell us more.