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Bug #79454: Inefficient InnoDB row stats implementation #123

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Bug #79454: Inefficient InnoDB row stats implementation #123

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1 change: 0 additions & 1 deletion storage/innobase/include/sync0types.h
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Original file line number Diff line number Diff line change
Expand Up @@ -30,7 +30,6 @@ Created 9/5/1995 Heikki Tuuri
#include <iostream>

#include "ut0new.h"
#include "ut0counter.h"

#if defined(UNIV_DEBUG) && !defined(UNIV_INNOCHECKSUM)
/** Set when InnoDB has invoked exit(). */
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23 changes: 22 additions & 1 deletion storage/innobase/include/ut0counter.h
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Expand Up @@ -30,6 +30,7 @@ Created 2012/04/12 by Sunny Bains
#include <my_rdtsc.h>
#include "univ.i"
#include "os0thread.h"
#include "ut0rnd.h"

/** CPU cache line size */
#ifdef __powerpc__
Expand All @@ -53,6 +54,22 @@ struct generic_indexer_t {
}
};

/** Use random numbers to index into the counter array. */
template <typename Type=ulint, int N=1>
struct get_rand_indexer_t : public generic_indexer_t<Type, N> {
/** Default constructor/destructor should be OK. */

enum { fast = 1 };

/* @return result from ut_rnd_gen_ulint(). */
static size_t get_rnd_index() UNIV_NOTHROW {

ulint idx = ut_rnd_gen_ulint();

return(size_t(idx));
}
};

/** Use the result of my_timer_cycles(), which mainly uses RDTSC for cycles,
to index into the counter array. See the comments for my_timer_cycles() */
template <typename Type=ulint, int N=1>
Expand Down Expand Up @@ -106,7 +123,11 @@ struct single_indexer_t {
}
};

#define default_indexer_t counter_indexer_t
#if defined(__aarch64__) && defined(UNIV_LINUX)
# define default_indexer_t get_rand_indexer_t
#else
# define default_indexer_t counter_indexer_t
#endif

/** Class for using fuzzy counters. The counter is not protected by any
mutex and the results are not guaranteed to be 100% accurate but close
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