diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/include/access/reloptions.h | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/src/include/access/reloptions.h b/src/include/access/reloptions.h index 146aed47c2d..dfbb4c85460 100644 --- a/src/include/access/reloptions.h +++ b/src/include/access/reloptions.h @@ -152,7 +152,19 @@ typedef struct const char *optname; /* option's name */ relopt_type opttype; /* option's datatype */ int offset; /* offset of field in result struct */ - int isset_offset; /* if > 0, offset of "is set" field */ + + /* + * isset_offset is an optional offset of a field in the result struct that + * stores whether the option is explicitly set for the relation or if it + * just picked up the default value. In most cases, this can be + * accomplished by giving the reloption a special out-of-range default + * value (e.g., some integer reloptions use -2), but this isn't always + * possible. For example, a Boolean reloption cannot be given an + * out-of-range default, so we need another way to discover the source of + * its value. This offset is only used if given a value greater than + * zero. + */ + int isset_offset; } relopt_parse_elt; /* Local reloption definition */ |