derived_keys.h File Reference

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Functions
bool	MakeDerivedKeys (THD *thd, JOIN *join)
	Collect the set fields of derived tables that are present in predicates like "derived_tab.field=function(other_tab.field)". More...
void	FinalizeDerivedKeys (THD *thd, const Query_block &query_block, AccessPath *root_path)
	Remove any unused keys on derived tables. More...

Function Documentation

FinalizeDerivedKeys()

void FinalizeDerivedKeys	(	THD *	thd,
		const Query_block &	query_block,
		AccessPath *	root_path
	)

Remove any unused keys on derived tables.

Update the key number in any AccessPath that uses a key that gets shifted to a lower number due to those removals.

Parameters

thd	The current thread.
query_block	The current Query_block.
root_path	The root path of 'query_block'.

MakeDerivedKeys()

bool MakeDerivedKeys	(	THD *	thd,
		JOIN *	join
	)

Collect the set fields of derived tables that are present in predicates like "derived_tab.field=function(other_tab.field)".

Generate keys for every derived_tab+other_tab pair in that set.

Parameters

thd	The current thread.
join	The current join.