I've accumulated another collection of various questions and comments. As a side note I'm getting a good feeling about this patch, those part I've read so far looks good to me.
* I've suddenly realized one could use pseudo types for variables, and it not always works. E.g.: =# create variable pseudo_array anyarray; =# select pseudo_array; pseudo_array -------------- NULL =# let pseudo_array = ARRAY[1, 2, 3]; ERROR: 42804: target session variable is of type anyarray but expression is of type integer[] LOCATION: svariableStartupReceiver, svariableReceiver.c:79 =# create variable pseudo_unknown unknown; =# select pseudo_unknown; ERROR: XX000: failed to find conversion function from unknown to text LOCATION: coerce_type, parse_coerce.c:542 Is it supposed to be like this, or something is missing? * I think it was already mentioned in the thread, there seems to be not a single usage of CHECK_FOR_INTERRUPTS in session_variable.c . But some number of loops over the sessionvars are implemented, are they always going to be small enough to not make any troubles? * sync_sessionvars_all explains why is it necessary to copy xact_recheck_varids: When we check the variables, the system cache can be invalidated, and xact_recheck_varids can be enhanced. I'm not quite following what the "enhancement" part is about? Is xact_recheck_varids could be somehow updated concurrently with the loop? * A small typo diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c --- a/src/backend/commands/session_variable.c +++ b/src/backend/commands/session_variable.c @@ -485,7 +485,7 @@ sync_sessionvars_all(bool filter_lxid) /* * When we check the variables, the system cache can be invalidated, - * and xac_recheck_varids can be enhanced. We want to iterate + * and xact_recheck_varids can be enhanced. We want to iterate NOTE: The commentaries above were made based on the previous patch version, but it looks like those aspects were not changed.