toastinfo
toastinfo
toastinfo : show details on toasted datums
Overview
| ID | Extension | Package | Version | Category | License | Language |
|---|---|---|---|---|---|---|
| 6530 | toastinfo | toastinfo | 1.5 | STAT | PostgreSQL | C |
| Attribute | Has Binary | Has Library | Need Load | Has DDL | Relocatable | Trusted |
|---|---|---|---|---|---|---|
--s-d-r | No | Yes | No | Yes | yes | no |
| Relationships | |
|---|---|
| See Also | pageinspect pg_visibility pgstattuple amcheck pg_relusage pg_buffercache pg_freespacemap pg_repack |
Packages
| Type | Repo | Version | PG Major Compatibility | Package Pattern | Dependencies |
|---|---|---|---|---|---|
| EXT | MIXED | 1.5 | 18 17 16 15 14 | toastinfo | - |
| RPM | PIGSTY | 1.5 | 18 17 16 15 14 | toastinfo_$v | - |
| DEB | PGDG | 1.5 | 18 17 16 15 14 | postgresql-$v-toastinfo | - |
| Linux / PG | PG18 | PG17 | PG16 | PG15 | PG14 |
|---|---|---|---|---|---|
el8.x86_64 | PIGSTY 1.5 | PIGSTY 1.5 | PIGSTY 1.5 | PIGSTY 1.5 | PIGSTY 1.5 |
el8.aarch64 | PIGSTY 1.5 | PIGSTY 1.5 | PIGSTY 1.5 | PIGSTY 1.5 | PIGSTY 1.5 |
el9.x86_64 | PIGSTY 1.5 | PIGSTY 1.5 | PIGSTY 1.5 | PIGSTY 1.5 | PIGSTY 1.5 |
el9.aarch64 | PIGSTY 1.5 | PIGSTY 1.5 | PIGSTY 1.5 | PIGSTY 1.5 | PIGSTY 1.5 |
el10.x86_64 | PIGSTY 1.5 | PIGSTY 1.5 | PIGSTY 1.5 | PIGSTY 1.5 | PIGSTY 1.5 |
el10.aarch64 | PIGSTY 1.5 | PIGSTY 1.5 | PIGSTY 1.5 | PIGSTY 1.5 | PIGSTY 1.5 |
d12.x86_64 | PGDG 1.5 | PGDG 1.5 | PGDG 1.5 | PGDG 1.5 | PGDG 1.5 |
d12.aarch64 | PGDG 1.5 | PGDG 1.5 | PGDG 1.5 | PGDG 1.5 | PGDG 1.5 |
d13.x86_64 | PGDG 1.5 | PGDG 1.5 | PGDG 1.5 | PGDG 1.5 | PGDG 1.5 |
d13.aarch64 | PGDG 1.5 | PGDG 1.5 | PGDG 1.5 | PGDG 1.5 | PGDG 1.5 |
u22.x86_64 | PGDG 1.5 | PGDG 1.5 | PGDG 1.5 | PGDG 1.5 | PGDG 1.5 |
u22.aarch64 | PGDG 1.5 | PGDG 1.5 | PGDG 1.5 | PGDG 1.5 | PGDG 1.5 |
u24.x86_64 | PGDG 1.5 | PGDG 1.5 | PGDG 1.5 | PGDG 1.5 | PGDG 1.5 |
u24.aarch64 | PGDG 1.5 | PGDG 1.5 | PGDG 1.5 | PGDG 1.5 | PGDG 1.5 |
Source
pig build pkg toastinfo; # build rpmInstall
Make sure PGDG and PIGSTY repo available:
pig repo add pgsql -u # add both repo and update cacheInstall this extension with pig:
pig install toastinfo; # install via package name, for the active PG version
pig install toastinfo -v 18; # install for PG 18
pig install toastinfo -v 17; # install for PG 17
pig install toastinfo -v 16; # install for PG 16
pig install toastinfo -v 15; # install for PG 15
pig install toastinfo -v 14; # install for PG 14Create this extension with:
CREATE EXTENSION toastinfo;Usage
toastinfo exposes the internal storage form of variable-length (varlena) data types, showing how PostgreSQL stores each datum.
Functions
pg_toastinfo(anyelement) – describes the storage form of a datum:
SELECT a, length(b), pg_column_size(b), pg_toastinfo(b), pg_toastpointer(b)
FROM t;
a | length | pg_column_size | pg_toastinfo | pg_toastpointer
------------------+---------+----------------+----------------------------------------+-----------------
null | * | * | null | *
default | 7 | 8 | short inline varlena | *
external-200 | 200 | 204 | long inline varlena, uncompressed | *
external-10000 | 10000 | 10000 | toasted varlena, uncompressed | 16427
extended-10000 | 10000 | 125 | long inline varlena, compressed (pglz) | *
extended-1000000 | 1000000 | 11452 | toasted varlena, compressed (pglz) | 16429
extended-1000000 | 1000000 | 3936 | toasted varlena, compressed (lz4) | 16430Possible storage forms:
null– NULL valuesordinary– non-varlena datatypesshort inline varlena– up to 126 bytes (1-byte header)long inline varlena, (un)compressed– up to 1GiB (4-byte header)toasted varlena, (un)compressed– up to 1GiB stored in TOAST table- Compressed varlenas show method (
pglz,lz4) on PG14+
pg_toastpointer(anyelement) – returns the chunk_id OID in the TOAST table, or NULL for non-toasted data:
SELECT pg_toastpointer(large_column) FROM my_table;Last updated on