## 20.18. Short Options

 For convenience there are also single letter command-line option switches available for some parameters. They are described in [Table 20.3](runtime-config-short.html#RUNTIME-CONFIG-SHORT-TABLE). Some of these options exist for historical reasons, and their presence as a single-letter option does not necessarily indicate an endorsement to use the option heavily.

**Table 20.3. Short Option Key**

|                     Short Option                      |                                                                                                  Equivalent                                                                                                  |
|-------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|                      `-B *`x`*`                       |                                                                                           `shared_buffers = *`x`*`                                                                                           |
|                      `-d *`x`*`                       |                                                                                       `log_min_messages = DEBUG*`x`*`                                                                                        |
|                         `-e`                          |                                                                                              `datestyle = euro`                                                                                              |
| `-fb`, `-fh`, `-fi`, `-fm`, `-fn`, `-fo`, `-fs`, `-ft`| `enable_bitmapscan = off`, `enable_hashjoin = off`, `enable_indexscan = off`, `enable_mergejoin = off`, `enable_nestloop = off`, `enable_indexonlyscan = off`, `enable_seqscan = off`, `enable_tidscan = off`|
|                         `-F`                          |                                                                                                `fsync = off`                                                                                                 |
|                      `-h *`x`*`                       |                                                                                          `listen_addresses = *`x`*`                                                                                          |
|                         `-i`                          |                                                                                           `listen_addresses = '*'`                                                                                           |
|                      `-k *`x`*`                       |                                                                                      `unix_socket_directories = *`x`*`                                                                                       |
|                         `-l`                          |                                                                                                  `ssl = on`                                                                                                  |
|                      `-N *`x`*`                       |                                                                                          `max_connections = *`x`*`                                                                                           |
|                         `-O`                          |                                                                                        `allow_system_table_mods = on`                                                                                        |
|                      `-p *`x`*`                       |                                                                                                `port = *`x`*`                                                                                                |
|                         `-P`                          |                                                                                         `ignore_system_indexes = on`                                                                                         |
|                         `-s`                          |                                                                                          `log_statement_stats = on`                                                                                          |
|                      `-S *`x`*`                       |                                                                                              `work_mem = *`x`*`                                                                                              |
|                 `-tpa`, `-tpl`, `-te`                 |                                                                 `log_parser_stats = on`, `log_planner_stats = on`, `log_executor_stats = on`                                                                 |
|                      `-W *`x`*`                       |                                                                                          `post_auth_delay = *`x`*`                                                                                           |

