[PATCH v2 2/4] Introduce ternary reloptions
Nikolay Shaplov <dhyan@nataraj.su>
From: Nikolay Shaplov <dhyan@nataraj.su>
To:
Date: 2025-09-04T14:41:39Z
Lists: pgsql-hackers
Introduce ternary reloption as a replacement for current `vacuum_truncate`
implementation. Remove `vacuum_truncate_set` additional flag and using
`TERNARY_UNSET` value instead.
---
src/backend/access/common/reloptions.c | 129 ++++++++++++++++++++-----
src/backend/commands/vacuum.c | 4 +-
src/include/access/reloptions.h | 26 ++---
src/include/c.h | 16 +++
src/include/utils/rel.h | 3 +-
5 files changed, 135 insertions(+), 43 deletions(-)
diff --git a/src/backend/access/common/reloptions.c b/src/backend/access/common/reloptions.c
index 0af3fea68f..f543f11001 100644
--- a/src/backend/access/common/reloptions.c
+++ b/src/backend/access/common/reloptions.c
@@ -40,9 +40,9 @@
*
* To add an option:
*
- * (i) decide on a type (bool, integer, real, enum, string), name, default
- * value, upper and lower bounds (if applicable); for strings, consider a
- * validation routine.
+ * (i) decide on a type (bool, ternary, integer, real, enum, string), name,
+ * default value, upper and lower bounds (if applicable); for strings,
+ * consider a validation routine.
* (ii) add a record below (or use add_<type>_reloption).
* (iii) add it to the appropriate options struct (perhaps StdRdOptions)
* (iv) add it to the appropriate handling routine (perhaps
@@ -147,15 +147,6 @@ static relopt_bool boolRelOpts[] =
},
false
},
- {
- {
- "vacuum_truncate",
- "Enables vacuum to truncate empty pages at the end of this table",
- RELOPT_KIND_HEAP | RELOPT_KIND_TOAST,
- ShareUpdateExclusiveLock
- },
- true
- },
{
{
"deduplicate_items",
@@ -170,6 +161,21 @@ static relopt_bool boolRelOpts[] =
{{NULL}}
};
+static relopt_ternary ternaryRelOpts[] =
+{
+ {
+ {
+ "vacuum_truncate",
+ "Enables vacuum to truncate empty pages at the end of this table",
+ RELOPT_KIND_HEAP | RELOPT_KIND_TOAST,
+ ShareUpdateExclusiveLock
+ },
+ TERNARY_UNSET
+ },
+ /* list terminator */
+ {{NULL}}
+};
+
static relopt_int intRelOpts[] =
{
{
@@ -600,6 +606,13 @@ initialize_reloptions(void)
boolRelOpts[i].gen.lockmode));
j++;
}
+ for (i = 0; ternaryRelOpts[i].gen.name; i++)
+ {
+ Assert(DoLockModesConflict(ternaryRelOpts[i].gen.lockmode,
+ ternaryRelOpts[i].gen.lockmode));
+ j++;
+ }
+
for (i = 0; intRelOpts[i].gen.name; i++)
{
Assert(DoLockModesConflict(intRelOpts[i].gen.lockmode,
@@ -640,6 +653,14 @@ initialize_reloptions(void)
j++;
}
+ for (i = 0; ternaryRelOpts[i].gen.name; i++)
+ {
+ relOpts[j] = &ternaryRelOpts[i].gen;
+ relOpts[j]->type = RELOPT_TYPE_TERNARY;
+ relOpts[j]->namelen = strlen(relOpts[j]->name);
+ j++;
+ }
+
for (i = 0; intRelOpts[i].gen.name; i++)
{
relOpts[j] = &intRelOpts[i].gen;
@@ -800,6 +821,9 @@ allocate_reloption(bits32 kinds, int type, const char *name, const char *desc,
case RELOPT_TYPE_BOOL:
size = sizeof(relopt_bool);
break;
+ case RELOPT_TYPE_TERNARY:
+ size = sizeof(relopt_ternary);
+ break;
case RELOPT_TYPE_INT:
size = sizeof(relopt_int);
break;
@@ -883,6 +907,54 @@ add_local_bool_reloption(local_relopts *relopts, const char *name,
add_local_reloption(relopts, (relopt_gen *) newoption, offset);
}
+/*
+ * init_ternary_reloption
+ * Allocate and initialize a new ternary reloption
+ */
+static relopt_ternary *
+init_ternary_reloption(bits32 kinds, const char *name, const char *desc,
+ ternary default_val, LOCKMODE lockmode)
+{
+ relopt_ternary *newoption;
+
+ newoption = (relopt_ternary *) allocate_reloption(kinds,
+ RELOPT_TYPE_TERNARY, name, desc, lockmode);
+ newoption->default_val = default_val;
+
+ return newoption;
+}
+
+/*
+ * add_ternary_reloption
+ * Add a new ternary reloption
+ */
+void
+add_ternary_reloption(bits32 kinds, const char *name, const char *desc,
+ ternary default_val, LOCKMODE lockmode)
+{
+ relopt_ternary *newoption = init_ternary_reloption(kinds, name, desc,
+ default_val, lockmode);
+
+ add_reloption((relopt_gen *) newoption);
+}
+
+/*
+ * add_local_ternary_reloption
+ * Add a new ternary local reloption
+ *
+ * 'offset' is offset of ternary-typed field.
+ */
+void
+add_local_ternary_reloption(local_relopts *relopts, const char *name,
+ const char *desc, ternary default_val,
+ int offset)
+{
+ relopt_ternary *newoption = init_ternary_reloption(RELOPT_KIND_LOCAL,
+ name, desc,
+ default_val, 0);
+
+ add_local_reloption(relopts, (relopt_gen *) newoption, offset);
+}
/*
* init_real_reloption
@@ -1617,6 +1689,18 @@ parse_one_reloption(relopt_value *option, char *text_str, int text_len,
option->gen->name, value)));
}
break;
+ case RELOPT_TYPE_TERNARY:
+ {
+ bool b;
+ parsed = parse_bool(value, &b);
+ option->values.ternary_val = b ? TERNARY_TRUE : TERNARY_FALSE;
+ if (validate && !parsed)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("invalid value for ternary option \"%s\": %s",
+ option->gen->name, value)));
+ }
+ break;
case RELOPT_TYPE_INT:
{
relopt_int *optint = (relopt_int *) option->gen;
@@ -1780,17 +1864,6 @@ fillRelOptions(void *rdopts, Size basesize,
char *itempos = ((char *) rdopts) + elems[j].offset;
char *string_val;
- /*
- * If isset_offset is provided, store whether the reloption is
- * set there.
- */
- if (elems[j].isset_offset > 0)
- {
- char *setpos = ((char *) rdopts) + elems[j].isset_offset;
-
- *(bool *) setpos = options[i].isset;
- }
-
switch (options[i].gen->type)
{
case RELOPT_TYPE_BOOL:
@@ -1798,6 +1871,11 @@ fillRelOptions(void *rdopts, Size basesize,
options[i].values.bool_val :
((relopt_bool *) options[i].gen)->default_val;
break;
+ case RELOPT_TYPE_TERNARY:
+ *(ternary *) itempos = options[i].isset ?
+ options[i].values.ternary_val :
+ ((relopt_ternary *) options[i].gen)->default_val;
+ break;
case RELOPT_TYPE_INT:
*(int *) itempos = options[i].isset ?
options[i].values.int_val :
@@ -1912,8 +1990,8 @@ default_reloptions(Datum reloptions, bool validate, relopt_kind kind)
offsetof(StdRdOptions, parallel_workers)},
{"vacuum_index_cleanup", RELOPT_TYPE_ENUM,
offsetof(StdRdOptions, vacuum_index_cleanup)},
- {"vacuum_truncate", RELOPT_TYPE_BOOL,
- offsetof(StdRdOptions, vacuum_truncate), offsetof(StdRdOptions, vacuum_truncate_set)},
+ {"vacuum_truncate", RELOPT_TYPE_TERNARY,
+ offsetof(StdRdOptions, vacuum_truncate)},
{"vacuum_max_eager_freeze_failure_rate", RELOPT_TYPE_REAL,
offsetof(StdRdOptions, vacuum_max_eager_freeze_failure_rate)}
};
@@ -1993,7 +2071,6 @@ build_local_reloptions(local_relopts *relopts, Datum options, bool validate)
elems[i].optname = opt->option->name;
elems[i].opttype = opt->option->type;
elems[i].offset = opt->offset;
- elems[i].isset_offset = 0; /* not supported for local relopts yet */
i++;
}
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 733ef40ae7..977babff54 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -2221,9 +2221,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
{
StdRdOptions *opts = (StdRdOptions *) rel->rd_options;
- if (opts && opts->vacuum_truncate_set)
+ if (opts && opts->vacuum_truncate != TERNARY_UNSET)
{
- if (opts->vacuum_truncate)
+ if (opts->vacuum_truncate == TERNARY_TRUE)
params.truncate = VACOPTVALUE_ENABLED;
else
params.truncate = VACOPTVALUE_DISABLED;
diff --git a/src/include/access/reloptions.h b/src/include/access/reloptions.h
index a604a4702c..a436697658 100644
--- a/src/include/access/reloptions.h
+++ b/src/include/access/reloptions.h
@@ -29,6 +29,7 @@
typedef enum relopt_type
{
RELOPT_TYPE_BOOL,
+ RELOPT_TYPE_TERNARY, /* on, off, unset */
RELOPT_TYPE_INT,
RELOPT_TYPE_REAL,
RELOPT_TYPE_ENUM,
@@ -80,6 +81,7 @@ typedef struct relopt_value
union
{
bool bool_val;
+ ternary ternary_val;
int int_val;
double real_val;
int enum_val;
@@ -94,6 +96,12 @@ typedef struct relopt_bool
bool default_val;
} relopt_bool;
+typedef struct relopt_rernary
+{
+ relopt_gen gen;
+ int default_val;
+} relopt_ternary;
+
typedef struct relopt_int
{
relopt_gen gen;
@@ -152,19 +160,6 @@ typedef struct
const char *optname; /* option's name */
relopt_type opttype; /* option's datatype */
int offset; /* offset of field in result struct */
-
- /*
- * 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 */
@@ -195,6 +190,8 @@ typedef struct local_relopts
extern relopt_kind add_reloption_kind(void);
extern void add_bool_reloption(bits32 kinds, const char *name, const char *desc,
bool default_val, LOCKMODE lockmode);
+extern void add_ternary_reloption(bits32 kinds, const char *name,
+ const char *desc, int default_val, LOCKMODE lockmode);
extern void add_int_reloption(bits32 kinds, const char *name, const char *desc,
int default_val, int min_val, int max_val,
LOCKMODE lockmode);
@@ -214,6 +211,9 @@ extern void register_reloptions_validator(local_relopts *relopts,
extern void add_local_bool_reloption(local_relopts *relopts, const char *name,
const char *desc, bool default_val,
int offset);
+extern void add_local_ternary_reloption(local_relopts *relopts,
+ const char *name, const char *desc,
+ ternary default_val, int offset);
extern void add_local_int_reloption(local_relopts *relopts, const char *name,
const char *desc, int default_val,
int min_val, int max_val, int offset);
diff --git a/src/include/c.h b/src/include/c.h
index 39022f8a9d..9c59ccccf8 100644
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -488,6 +488,22 @@ typedef void (*pg_funcptr_t) (void);
#include <stdbool.h>
+/*
+ * ternary
+ * Boolean value with an extrea "unset" option
+ *
+ * Ternary data type is used in relation options that can be "true", "false" or
+ * "unset". Since relation options are used deep inside the PostgreSQL code,
+ * this type is declared globally.
+*/
+
+typedef enum ternary
+{
+ TERNARY_FALSE = 0,
+ TERNARY_TRUE = 1,
+ TERNARY_UNSET = -1
+} ternary;
+
/* ----------------------------------------------------------------
* Section 3: standard system types
diff --git a/src/include/utils/rel.h b/src/include/utils/rel.h
index b552359915..7346d618f9 100644
--- a/src/include/utils/rel.h
+++ b/src/include/utils/rel.h
@@ -346,8 +346,7 @@ typedef struct StdRdOptions
bool user_catalog_table; /* use as an additional catalog relation */
int parallel_workers; /* max number of parallel workers */
StdRdOptIndexCleanup vacuum_index_cleanup; /* controls index vacuuming */
- bool vacuum_truncate; /* enables vacuum to truncate a relation */
- bool vacuum_truncate_set; /* whether vacuum_truncate is set */
+ ternary vacuum_truncate; /* enables vacuum to truncate a relation */
/*
* Fraction of pages in a relation that vacuum can eagerly scan and fail
--
2.39.2
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