wppaste
WordPress

get_meta_keys(): string[]

Since
1.2.0
Source
wp-admin/includes/post.php:1064
Returns a list of previously defined keys.

Compatibility

WordPress
since 1.2.0
PHP
7.4–8.6-dev
  • 6.7.7
  • 6.8.8
  • 6.9.7
  • 7.0.4
  • 7.1.0

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Return value

string[]
Array of meta key names.

Performance profile

How much work a call to get_meta_keys() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.

Cost class
Trivial

Reaches the database via ->get_col().

Scaling
Constant

No loop in the body: the same number of instructions runs whatever you pass in.

Instructions
10

Executed per call on PHP 8.5. The body compiles to 10.

Plugin surface
None

Nothing here hands control to plugin code.

Called by
0

Nothing in core calls this; the cost is only what you spend yourself.

What it touches

  • sqldatabase query->get_col()called directly

What one call costs · 1 distinct outcome

One number would be a lie: the work depends on which branch runs. These are every distinct cost get_meta_keys() can have, taken from its control-flow graph on PHP 8.5.

WhenInstructionsCalls it makes
always10->get_col()

Across PHP versions

Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 10 instructions, 10 executed per call, 0 branches. The work does not change between versions.

An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.

Source code

View on Trac View on GitHub 

function get_meta_keys() {	global $wpdb; 	$keys = $wpdb->get_col(		"SELECT meta_key		FROM $wpdb->postmeta		GROUP BY meta_key		ORDER BY meta_key"	); 	return $keys;}

Changelog

Introduced in 1.2.0. Unchanged from 6.7.7 through 7.1.0.

  1. 6.7.7
  2. 6.8.8
  3. 6.9.7
  4. 7.0.4
  5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data
Generated from the wordpress-develop 7.1.0 tag, from src/wp-admin/includes/post.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.
Corrections
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