Sel_arg_range_sequence Class Reference

Public Member Functions
	Sel_arg_range_sequence (RANGE_OPT_PARAM *param_arg, bool *is_ror_scan_arg, uchar *min_key_arg, uchar *max_key_arg, bool skip_records_in_range_arg)
void	reset ()
bool	stack_empty () const
void	stack_push_range (SEL_ARG *key_tree)
void	stack_pop_range ()
int	stack_size () const
RANGE_SEQ_ENTRY *	stack_top ()

Public Attributes
uint	keyno
uint	real_keyno
RANGE_OPT_PARAM *const	param
bool *	is_ror_scan
uchar *	min_key
uchar *	max_key
const bool	skip_records_in_range
SEL_ARG *	start
uint	range_count = 0
uint	max_key_part

Private Attributes
RANGE_SEQ_ENTRY	stack [MAX_REF_PARTS]
	Stack of ranges for the curr_kp first keyparts. More...
int	curr_kp

Constructor & Destructor Documentation

Sel_arg_range_sequence()

Sel_arg_range_sequence::Sel_arg_range_sequence ( RANGE_OPT_PARAM *  param_arg, bool *  is_ror_scan_arg, uchar *  min_key_arg, uchar *  max_key_arg, bool  skip_records_in_range_arg  )

inline

Member Function Documentation

reset()

void Sel_arg_range_sequence::reset ( void  )

inline

stack_empty()

bool Sel_arg_range_sequence::stack_empty ( ) const

inline

stack_pop_range()

void Sel_arg_range_sequence::stack_pop_range ( )

inline

stack_push_range()

void Sel_arg_range_sequence::stack_push_range

(

SEL_ARG *

key_tree

)

stack_size()

int Sel_arg_range_sequence::stack_size ( ) const

inline

stack_top()

RANGE_SEQ_ENTRY * Sel_arg_range_sequence::stack_top ( )

inline

Member Data Documentation

curr_kp

int Sel_arg_range_sequence::curr_kp

private

is_ror_scan

bool* Sel_arg_range_sequence::is_ror_scan

keyno

uint Sel_arg_range_sequence::keyno

max_key

uchar * Sel_arg_range_sequence::max_key

max_key_part

uint Sel_arg_range_sequence::max_key_part

min_key

uchar* Sel_arg_range_sequence::min_key

param

RANGE_OPT_PARAM* const Sel_arg_range_sequence::param

range_count

uint Sel_arg_range_sequence::range_count = 0

real_keyno

uint Sel_arg_range_sequence::real_keyno

skip_records_in_range

const bool Sel_arg_range_sequence::skip_records_in_range

stack

RANGE_SEQ_ENTRY Sel_arg_range_sequence::stack[MAX_REF_PARTS]

private

Stack of ranges for the curr_kp first keyparts.

Used by sel_arg_range_seq_next() so that if the next range is equal to the previous one for the first x keyparts, stack[x-1] can be accumulated with the new range in keyparts > x to quickly form the next range to return.

Notation used below: "x:y" means a range where "column_in_keypart_0=x" and "column_in_keypart_1=y". For simplicity, only equality (no BETWEEN, < etc) is considered in the example but the same principle applies to other range predicate operators too.

Consider a query with these range predicates: (kp0=1 and kp1=2 and kp2=3) or (kp0=1 and kp1=2 and kp2=4) or (kp0=1 and kp1=3 and kp2=5) or (kp0=1 and kp1=3 and kp2=6)

1) sel_arg_range_seq_next() is called the first time

• traverse the R-B tree (see SEL_ARG) to find the first range
• returns range "1:2:3"
• values in stack after this: stack[1, 1:2, 1:2:3] 2) sel_arg_range_seq_next() is called second time
• keypart 2 has another range, so the next range in keypart 2 is appended to stack[1] and saved in stack[2]
• returns range "1:2:4"
• values in stack after this: stack[1, 1:2, 1:2:4] 3) sel_arg_range_seq_next() is called the third time
• no more ranges in keypart 2, but keypart 1 has another range, so the next range in keypart 1 is appended to stack[0] and saved in stack[1]. The first range in keypart 2 is then appended to stack[1] and saved in stack[2]
• returns range "1:3:5"
• values in stack after this: stack[1, 1:3, 1:3:5] 4) sel_arg_range_seq_next() is called the fourth time
• keypart 2 has another range, see 2)
• returns range "1:3:6"
• values in stack after this: stack[1, 1:3, 1:3:6]

start

SEL_ARG* Sel_arg_range_sequence::start

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The documentation for this class was generated from the following file:

• sql/range_optimizer/index_range_scan_plan.cc