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Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/pltcl.sgml | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/doc/src/sgml/pltcl.sgml b/doc/src/sgml/pltcl.sgml index b31f2c1330f..5a8e4c9d37e 100644 --- a/doc/src/sgml/pltcl.sgml +++ b/doc/src/sgml/pltcl.sgml @@ -1120,16 +1120,25 @@ CALL transaction_test1(); <para> In <productname>PostgreSQL</productname>, the same function name can be used for - different function definitions as long as the number of arguments or their types + different function definitions if the functions are placed in different + schemas, or if the number of arguments or their types differ. Tcl, however, requires all procedure names to be distinct. - PL/Tcl deals with this by making the internal Tcl procedure names contain - the object - ID of the function from the system table <structname>pg_proc</structname> as part of their name. Thus, + PL/Tcl deals with this by including the argument type names in the + internal Tcl procedure name, and then appending the function's object + ID (OID) to the internal Tcl procedure name if necessary to make it + different from the names of all previously-loaded functions in the + same Tcl interpreter. Thus, <productname>PostgreSQL</productname> functions with the same name and different argument types will be different Tcl procedures, too. This is not normally a concern for a PL/Tcl programmer, but it might be visible when debugging. </para> + <para> + For this reason among others, a PL/Tcl function cannot call another one + directly (that is, within Tcl). If you need to do that, you must go + through SQL, using <function>spi_exec</function> or a related command. + </para> + </sect1> </chapter> |