52.55. pg\_transform

|      52.55. `pg_transform`       |                   |                           |                  |                                |
|:--------------------------------:|-------------------|---------------------------|------------------|--------------------------------|
|[Prev](catalog-pg-tablespace.html)|[Up](catalogs.html)|Chapter 52. System Catalogs|[Home](index.html)| [Next](catalog-pg-trigger.html)|

---

## 52.55. `pg_transform`

[]()

 The catalog `pg_transform` stores information about transforms, which are a mechanism to adapt data types to procedural languages. See [CREATE TRANSFORM](sql-createtransform.html) for more information.

**Table 52.55. `pg_transform` Columns**

|                                                                                                                     Column Type<br/><br/> Description                                                                                                                     |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|                                                                                                                   `oid` `oid`<br/><br/> Row identifier                                                                                                                    |
|                                                                         `trftype` `oid` (references [`pg_type`](catalog-pg-type.html).`oid`)<br/><br/> OID of the data type this transform is for                                                                         |
|                                                                     `trflang` `oid` (references [`pg_language`](catalog-pg-language.html).`oid`)<br/><br/> OID of the language this transform is for                                                                      |
|`trffromsql` `regproc` (references [`pg_proc`](catalog-pg-proc.html).`oid`)<br/><br/> The OID of the function to use when converting the data type for input to the procedural language (e.g., function parameters). Zero is stored if the default behavior should be used.|
|   `trftosql` `regproc` (references [`pg_proc`](catalog-pg-proc.html).`oid`)<br/><br/> The OID of the function to use when converting output from the procedural language (e.g., return values) to the data type. Zero is stored if the default behavior should be used.   |

---

|[Prev](catalog-pg-tablespace.html)|[Up](catalogs.html)| [Next](catalog-pg-trigger.html)|
|:---------------------------------|:-----------------:|-------------------------------:|
|      52.54. `pg_tablespace`      |[Home](index.html) |       52.56. `pg_trigger`      |

 // \<![CDATA[ \<-- For SVG support if ('WebSocket' in window) { (function() { function refreshCSS() { var sheets = [].slice.call(document.getElementsByTagName("link")); var head = document.getElementsByTagName("head")[0]; for (var i = 0; i \< sheets.length; ++i) { var elem = sheets[i]; head.removeChild(elem); var rel = elem.rel; if (elem.href && typeof rel != "string" || rel.length == 0 || rel.toLowerCase() == "stylesheet") { var url = elem.href.replace(/(&|\\?)\_cacheOverride=\\d+/, ''); elem.href = url + (url.indexOf('?') \>= 0 ? '&' : '?') + '\_cacheOverride=' + (new Date().valueOf()); } head.appendChild(elem); } } var protocol = window.location.protocol === 'http:' ? 'ws://' : 'wss://'; var address = protocol + window.location.host + window.location.pathname + '/ws'; var socket = new WebSocket(address); socket.onmessage = function(msg) { if (msg.data == 'reload') window.location.reload(); else if (msg.data == 'refreshcss') refreshCSS(); }; console.log('Live reload enabled.'); })(); } // ]]\>