# Contrib Modules

> Changes to contrib extensions and the modules covered by the source document.

---

LLMS index: [llms.txt](/en/llms.txt)

---

<div class="feature-source-note"><span class="feature-edition-badge">GA</span><span><strong>Source pages:</strong> PDF 65-70</span><span><a href="https://github.com/nori-shinoda/documents/blob/1773200c5362476c4a549222b7d17fa91f546cae/postgresql15_ga_new_features_en_20221014-1.pdf">Original PDF on GitHub</a></span></div>

<p class="feature-page-marker" id="pgfeat-15-modules-pdf-page-65">PDF page 65</p>

Describes new features related to the Contrib modules.

#### 3.5.1 Amcheck {#pg15-3-5-1-amcheck}

A sequence checking is now supported.

**Example 76.** Sequence checking

```text
postgres=# CREATE SEQUENCE seq1 ;
CREATE SEQUENCE
postgres=# SELECT verify_heapam(relation=>'seq1') ;
 verify_heapam
---------------
(0 rows)
```

#### 3.5.2 Basebackup_to_shell {#pg15-3-5-2-basebackup-to-shell}

This module is used when "shell" is specified as the target of the base backup. When using this module, specify basebackup_to_shell in the parameter shared_preload_libraries or local_preload_libraries. The following parameters can be specified:

**Table 24.** Available parameters

| Parameter name | Description |
| --- | --- |
| basebackup_to_shell.command | Command path to be executed |
| basebackup_to_shell.required_role | Roles required for execution |

#### 3.5.3 File_fdw {#pg15-3-5-3-file-fdw}

The MATCH value can now be specified in the HEADER option of the CREATE FOREIGN TABLE statement. This option checks for a match between the header line and column name in the text file.

<p class="feature-page-marker" id="pgfeat-15-modules-pdf-page-66">PDF page 66</p>

**Example 77.** Header match check

```text
postgres=# \! cat /tmp/data1.csv
c1,c3
1,data1
2,data2
postgres=# CREATE EXTENSION file_fdw ;
CREATE EXTENSION
postgres=# CREATE SERVER filesvr1 FOREIGN DATA WRAPPER file_fdw ;
CREATE SERVER
postgres=# CREATE FOREIGN TABLE head1 (c1 int, c2 text) SERVER filesvr1
OPTIONS (format 'csv', filename '/tmp/data1.csv', delimiter ',',
header 'match') ;
CREATE FOREIGN TABLE
postgres=# SELECT * FROM head1 ;
ERROR:  column name mismatch in header line field 2: got "c3", expected "c2"
CONTEXT:  COPY head1, line 1: "c1,c3"
```

#### 3.5.4 Pg_stat_statements {#pg15-3-5-4-pg-stat-statements}

The pg_stat_statements view has additional items that can be monitored.

##### I/O information for temporary files {#pg15-p66-i-o-information-for-temporary-files}

Read/write times for temporary files can now be monitored. The following columns have been added to the pg_stat_statements view.

**Table 25.** Added column

| Column name | Data type | Description |
| --- | --- | --- |
| temp_blk_read_time | double precision | Temporary block read time |
| temp_blk_write_time | double precision | Temporary block write time |

##### Addition of JIT-related information {#pg15-p66-addition-of-jit-related-information}

JIT-related information can now be monitored; the following columns have been added to the pg_stat_statements view.

<p class="feature-page-marker" id="pgfeat-15-modules-pdf-page-67">PDF page 67</p>

**Table 26.** Added column

| Column name | Data type | Description |
| --- | --- | --- |
| jit_functions | bigint | Number of JIT-compiled function executions |
| jit_generation_time | double precision | JIT code generation time (milliseconds) |
| jit_inlining_count | bigint | Number of executions of inlined function |
| jit_inlining_time | double precision | Execution time of inlined function (milliseconds) |
| jit_optimization_count | bigint | Optimized statement execution count |
| jit_optimization_time | double precision | Optimized statement execution time (milliseconds) |
| jit_emission_count | bigint | Number of times the code was issued |
| jit_emission_time | double precision | Time (milliseconds) the code was used to issue |

#### 3.5.5 Pg_walinspect {#pg15-3-5-5-pg-walinspect}

The pg_walinspect module is a module for executing processing similar to the pg_waldump command with SQL statements. The following functions are provided. These functions can only be executed by users with the SUPERUSER attribute or the pg_read_server_files role.

**Table 27.** Provided functions

| Function name | Description |
| --- | --- |
| pg_get_wal_record_info | Return WAL information for the specified LSN |
| pg_get_wal_records_info | Return WAL information between specified LSNs |
| pg_get_wal_records_info_till_end_of_wal | Return WAL information from the specified LSN to the end |
| pg_get_wal_stats | Return WAL statistics between specified LSNs |
| pg_get_wal_stats_till_end_of_wal | Return WAL statistics from the specified LSN to the end |

<p class="feature-page-marker" id="pgfeat-15-modules-pdf-page-68">PDF page 68</p>

**Example 78.** Execute the pg\_get\_wal\_stats function

```text
postgres=# CREATE EXTENSION pg_walinspect ;
CREATE EXTENSION
postgres=# SELECT * FROM pg_get_wal_stats('0/B4BB822'::pg_lsn ,
 '0/B4BB828'::pg_lsn) ;
-[ RECORD 1 ]----------------+------------------
resource_manager/record_type | XLOG
count                        | 0
count_percentage             | 0
…
```

#### 3.5.6 Postgres_fdw {#pg15-3-5-6-postgres-fdw}

The following enhancements have been implemented in postgres_fdw:

##### Specifying the application name {#pg15-p68-specifying-the-application-name}

It is now possible to specify application_name for a remote connection. Change the postgres_fdw.application_name parameter.

**Example 79.** Specify application name

```text
postgres=# SET postgres_fdw.application_name TO 'fdw_name1' ;
SET
postgres=# CREATE SERVER svr5432 FOREIGN DATA WRAPPER postgres_fdw OPTIONS
(host 'remhost1', port '5432', dbname 'postgres') ;
CREATE SERVER
```

```text
The following escape sequences can be specified in the application name.
```

<p class="feature-page-marker" id="pgfeat-15-modules-pdf-page-69">PDF page 69</p>

**Table 28.** Available escape sequences

| Escape sequence | Description | Note |
| --- | --- | --- |
| %a | Local application name |  |
| %c | Session ID |  |
| %C | Cluster name (cluster_name) |  |
| %d | Local database name |  |
| %p | Backend process ID |  |
| %u | Local user name |  |
| %% | % character |  |

##### Parallel_commit option {#pg15-p69-parallel-commit-option}

Added the parallel_commit option to control how remote transaction commits are executed. Setting this option to 'on' allows remote transaction commits in parallel. The default value is off, which causes commits to be executed serially.

**Example 80.** Specify parallel\_commit option

```text
postgres=# CREATE SERVER svr5433 FOREIGN DATA WRAPPER postgres_fdw OPTIONS
( host 'remhost1', port '5433', dbname 'postgres', parallel_commit 'true') ;
CREATE SERVER
postgres=# SELECT srvoptions FROM pg_foreign_server WHERE srvname='svr5433' ;
                           srvoptions
-----------------------------------------------------------------
 {host=localhost,port=5433,dbname=postgres,parallel_commit=true}
(1 row)
```

##### CASE expression {#pg15-p69-case-expression}

CASE expressions are now pushed to remote instances.

<p class="feature-page-marker" id="pgfeat-15-modules-pdf-page-70">PDF page 70</p>

**Example 81.** Pushed CASE expression

```text
postgres=> EXPLAIN (ANALYZE, VERBOSE) SELECT COUNT(*) FROM remote1 WHERE
CASE WHEN c1 > 100 THEN c1 END < 100 ;
                                 QUERY PLAN
-----------------------------------------------------------------------------
 Foreign Scan  (cost=102.84..164.07 rows=1 width=8) (actual time=1.364..1.365
rows=1 loops=1)
   Output: (count(*))
   Relations: Aggregate on (public.remote1)
   Remote SQL: SELECT count(*) FROM public.remote1 WHERE (((CASE WHEN (c1 >
100::numeric) THEN c1 ELSE NULL::numeric END) < 100::numeric))
 Planning Time: 0.077 ms
 Execution Time: 1.620 ms
(6 rows)
```

#### 3.5.7 Sepgsql {#pg15-3-5-7-sepgsql}

The permissive/enforcing state has been added to the log, with permissive=0 or permissive=1 output at the end of the line.