Re: pgbench: extend variable usage in scripts

pá 29. 8. 2025 v 9:23 odesílatel Yugo Nagata <nagata(at)sraoss(dot)co(dot)jp> napsal:

> Hi,
>
> I would like to propose patches to extend variable usage in pgbench
> scripts.
>
> * 0001: Allow variables to be used as an SQL literal or identifier
>
> Currently, variables in pgbench scripts are expanded always without
> quotes, so they cannot be used as SQL literals or identifiers.
> This patch allows the use of :'var' and :"var" in addition to :var
>
> However, they can used only in SQL commands, not in the arguments of
> meta-commands, since exprscan.l (the lexical scanner for pgbench backslash
> commands) cannot currently handle quoted values.
>
> Also, we have to use \aset, \gset or -D option to assign a string to a
> varialbe,
> since pgbench's \set command cannot recognize text values in its arguments.
>
> * 0002: Add syntax for variable exisitence check
>
> Currently, pgbench does not support :{?var} syntax to check whether the
> variable
> is defined or not. This patch adds support for this syntax in meta-command
> arguments.
> This is useful for checking if \aset set the result to the variable or not.
>
> However, it cannot be used in SQL statements for now.
>
>
> Some of the current limitations described above might be relaxed in the
> future, but
> for now, I would like to ask for initial feedback on this proposal.
>

+1

Regards

Pavel

>
> Regards,
> Yugo Nagata
>
> --
> Yugo Nagata <nagata(at)sraoss(dot)co(dot)jp>
>