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Note that zigzag joins are on by default in 19.2
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Fixes #4881.
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rmloveland committed Nov 5, 2019
1 parent 19653bd commit 54cde4e
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Showing 2 changed files with 13 additions and 2 deletions.
12 changes: 12 additions & 0 deletions _includes/v19.2/misc/session-vars.html
Expand Up @@ -95,6 +95,18 @@
<td>Yes</td>
</tr>

<tr>
<td>
<code>enable_zig_zag_join</code>
</td>
<td>Indicates whether the <a href="cost-based-optimizer.html">cost-based optimizer</a> will plan certain queries using a zig-zag merge join algorithm, which searches for the desired intersection by jumping back and forth between the indexes based on the fact that after constraining indexes, they share an ordering. </td>
<td>
<code>on</code>
</td>
<td>Yes</td>
<td>Yes</td>
</tr>

<tr>
<td>
<code>extra_float_digits</code>
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3 changes: 1 addition & 2 deletions v19.2/experimental-features.md
Expand Up @@ -20,8 +20,7 @@ The table below lists the experimental session settings that are available. For
| Variable | Default Value | Description |
|-------------------------------------+---------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `experimental_force_split_at` | `'off'` | Indicates whether checks to prevent incorrect usage of [`ALTER TABLE ... SPLIT AT`](split-at.html) should be skipped. |
| `experimental_enable_zigzag_join` | `'off'` | Indicates whether the [cost-based optimizer](cost-based-optimizer.html) will plan certain queries using a zig-zag merge join algorithm, which searches for the desired intersection by jumping back and forth between the indexes based on the fact that they share a sorted order in their key suffix. |
| `experimental_serial_normalization` | `'rowid'` | If set to `'virtual_sequence'`, make the [`SERIAL`](serial.html) pseudo-type optionally auto-create a sequence for [better compatibility with Hibernate sequences](https://forum.cockroachlabs.com/t/hibernate-sequence-generator-returns-negative-number-and-ignore-unique-rowid/).
| `experimental_serial_normalization` | `'rowid'` | If set to `'virtual_sequence'`, make the [`SERIAL`](serial.html) pseudo-type optionally auto-create a sequence for [better compatibility with Hibernate sequences](https://forum.cockroachlabs.com/t/hibernate-sequence-generator-returns-negative-number-and-ignore-unique-rowid/). |

## SQL statements

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