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WordPress

wp_should_upgrade_global_tables(): bool

Since
4.3.0
Source
wp-admin/includes/upgrade.php:3816
Determine if global tables should be upgraded.

Description

This function performs a series of checks to ensure the environment allows for the safe upgrading of global WordPress database tables. It is necessary because global tables will commonly grow to millions of rows on large installations, and the ability to control their upgrade routines can be critical to the operation of large networks.

In a future iteration, this function may use wp_is_large_network() to more- intelligently prevent global table upgrades. Until then, we make sure WordPress is on the main site of the main network, to avoid running queries more than once in multi-site or multi-network environments.

Compatibility

WordPress
since 4.3.0
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

bool
Whether to run the upgrade routines on global tables.

Performance profile

How much work a call to wp_should_upgrade_global_tables() 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

Touches nothing outside its own arguments.

Scaling
Constant

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

Instructions
3–16

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 17.

Plugin surface
1 hook

Third-party callbacks on 'wp_should_upgrade_global_tables' run inside this call, and their cost is not bounded by anything here.

Called by
8

8 places in core call this, so the cost is paid more often than your own code shows.

What it touches

  • hookthird-party callbacksapply_filters()called directly

What one call costs · 2 distinct outcomes

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

WhenInstructionsCalls it makes
defined('DO_NOT_UPGRADE_GLOBAL_TABLES')3none
!defined('DO_NOT_UPGRADE_GLOBAL_TABLES')14–16is_main_network(), is_main_site(), apply_filters()

Across PHP versions

Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 17 instructions, 3–16 executed per call, 3 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.

Hooks and filters fired · 1

One hook fires while wp_should_upgrade_global_tables() runs, in this order:

  1. apply_filters( wp_should_upgrade_global_tables )filterline 3843 (+27 into the body)

    Filters if upgrade routines should be run on global tables.

Uses · 3

  • is_main_network()Determines whether a network is the main network of the Multisite installation.
  • is_main_site()Determines whether a site is the main site of the current network.
  • apply_filters()Calls the callback functions that have been added to a filter hook.

Used by · 8

Source code

function wp_should_upgrade_global_tables() { 	// Return false early if explicitly not upgrading.	if ( defined( 'DO_NOT_UPGRADE_GLOBAL_TABLES' ) ) {		return false;	} 	// Assume global tables should be upgraded.	$should_upgrade = true; 	// Set to false if not on main network (does not matter if not multi-network).	if ( ! is_main_network() ) {		$should_upgrade = false;	} 	// Set to false if not on main site of current network (does not matter if not multi-site).	if ( ! is_main_site() ) {		$should_upgrade = false;	} 	/**	 * Filters if upgrade routines should be run on global tables.	 *	 * @since 4.3.0	 *	 * @param bool $should_upgrade Whether to run the upgrade routines on global tables.	 */	return apply_filters( 'wp_should_upgrade_global_tables', $should_upgrade );}

Changelog

Introduced in 4.3.0. 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/upgrade.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.
Corrections
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