Detect redundant GROUP BY columns using UNIQUE indexes

[pgsql.git] / src / test / modules / test_integerset / test_integerset.c

/*--------------------------------------------------------------------------
 *
 * test_integerset.c
 *              Test integer set data structure.
 *
 * Copyright (c) 2019-2024, PostgreSQL Global Development Group
 *
 * IDENTIFICATION
 *              src/test/modules/test_integerset/test_integerset.c
 *
 * -------------------------------------------------------------------------
 */
#include "postgres.h"

#include "common/pg_prng.h"
#include "fmgr.h"
#include "lib/integerset.h"
#include "utils/memutils.h"
#include "utils/timestamp.h"

/*
 * If you enable this, the "pattern" tests will print information about
 * how long populating, probing, and iterating the test set takes, and
 * how much memory the test set consumed.  That can be used as
 * micro-benchmark of various operations and input patterns (you might
 * want to increase the number of values used in each of the test, if
 * you do that, to reduce noise).
 *
 * The information is printed to the server's stderr, mostly because
 * that's where MemoryContextStats() output goes.
 */
static const bool intset_test_stats = false;

PG_MODULE_MAGIC;

PG_FUNCTION_INFO_V1(test_integerset);

/*
 * A struct to define a pattern of integers, for use with the test_pattern()
 * function.
 */
typedef struct
{
        char       *test_name;          /* short name of the test, for humans */
        char       *pattern_str;        /* a bit pattern */
        uint64          spacing;                /* pattern repeats at this interval */
        uint64          num_values;             /* number of integers to set in total */
} test_spec;

static const test_spec test_specs[] = {
        {
                "all ones", "1111111111",
                10, 10000000
        },
        {
                "alternating bits", "0101010101",
                10, 10000000
        },
        {
                "clusters of ten", "1111111111",
                10000, 10000000
        },
        {
                "clusters of hundred",
                "1111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111",
                10000, 100000000
        },
        {
                "one-every-64k", "1",
                65536, 10000000
        },
        {
                "sparse", "100000000000000000000000000000001",
                10000000, 10000000
        },
        {
                "single values, distance > 2^32", "1",
                UINT64CONST(10000000000), 1000000
        },
        {
                "clusters, distance > 2^32", "10101010",
                UINT64CONST(10000000000), 10000000
        },
        {
                "clusters, distance > 2^60", "10101010",
                UINT64CONST(2000000000000000000),
                23                                              /* can't be much higher than this, or we
                                                                 * overflow uint64 */
        }
};

static void test_pattern(const test_spec *spec);
static void test_empty(void);
static void test_single_value(uint64 value);
static void check_with_filler(IntegerSet *intset, uint64 x, uint64 value, uint64 filler_min, uint64 filler_max);
static void test_single_value_and_filler(uint64 value, uint64 filler_min, uint64 filler_max);
static void test_huge_distances(void);

/*
 * SQL-callable entry point to perform all tests.
 */
Datum
test_integerset(PG_FUNCTION_ARGS)
{
        /* Tests for various corner cases */
        test_empty();
        test_huge_distances();
        test_single_value(0);
        test_single_value(1);
        test_single_value(PG_UINT64_MAX - 1);
        test_single_value(PG_UINT64_MAX);
        test_single_value_and_filler(0, 1000, 2000);
        test_single_value_and_filler(1, 1000, 2000);
        test_single_value_and_filler(1, 1000, 2000000);
        test_single_value_and_filler(PG_UINT64_MAX - 1, 1000, 2000);
        test_single_value_and_filler(PG_UINT64_MAX, 1000, 2000);

        /* Test different test patterns, with lots of entries */
        for (int i = 0; i < lengthof(test_specs); i++)
        {
                test_pattern(&test_specs[i]);
        }

        PG_RETURN_VOID();
}

/*
 * Test with a repeating pattern, defined by the 'spec'.
 */
static void
test_pattern(const test_spec *spec)
{
        IntegerSet *intset;
        MemoryContext intset_ctx;
        MemoryContext old_ctx;
        TimestampTz starttime;
        TimestampTz endtime;
        uint64          n;
        uint64          last_int;
        int                     patternlen;
        uint64     *pattern_values;
        uint64          pattern_num_values;

        elog(NOTICE, "testing intset with pattern \"%s\"", spec->test_name);
        if (intset_test_stats)
                fprintf(stderr, "-----\ntesting intset with pattern \"%s\"\n", spec->test_name);

        /* Pre-process the pattern, creating an array of integers from it. */
        patternlen = strlen(spec->pattern_str);
        pattern_values = palloc(patternlen * sizeof(uint64));
        pattern_num_values = 0;
        for (int i = 0; i < patternlen; i++)
        {
                if (spec->pattern_str[i] == '1')
                        pattern_values[pattern_num_values++] = i;
        }

        /*
         * Allocate the integer set.
         *
         * Allocate it in a separate memory context, so that we can print its
         * memory usage easily.  (intset_create() creates a memory context of its
         * own, too, but we don't have direct access to it, so we cannot call
         * MemoryContextStats() on it directly).
         */
        intset_ctx = AllocSetContextCreate(CurrentMemoryContext,
                                                                           "intset test",
                                                                           ALLOCSET_SMALL_SIZES);
        MemoryContextSetIdentifier(intset_ctx, spec->test_name);
        old_ctx = MemoryContextSwitchTo(intset_ctx);
        intset = intset_create();
        MemoryContextSwitchTo(old_ctx);

        /*
         * Add values to the set.
         */
        starttime = GetCurrentTimestamp();

        n = 0;
        last_int = 0;
        while (n < spec->num_values)
        {
                uint64          x = 0;

                for (int i = 0; i < pattern_num_values && n < spec->num_values; i++)
                {
                        x = last_int + pattern_values[i];

                        intset_add_member(intset, x);
                        n++;
                }
                last_int += spec->spacing;
        }

        endtime = GetCurrentTimestamp();

        if (intset_test_stats)
                fprintf(stderr, "added " UINT64_FORMAT " values in %d ms\n",
                                spec->num_values, (int) (endtime - starttime) / 1000);

        /*
         * Print stats on the amount of memory used.
         *
         * We print the usage reported by intset_memory_usage(), as well as the
         * stats from the memory context.  They should be in the same ballpark,
         * but it's hard to automate testing that, so if you're making changes to
         * the implementation, just observe that manually.
         */
        if (intset_test_stats)
        {
                uint64          mem_usage;

                /*
                 * Also print memory usage as reported by intset_memory_usage().  It
                 * should be in the same ballpark as the usage reported by
                 * MemoryContextStats().
                 */
                mem_usage = intset_memory_usage(intset);
                fprintf(stderr, "intset_memory_usage() reported " UINT64_FORMAT " (%0.2f bytes / integer)\n",
                                mem_usage, (double) mem_usage / spec->num_values);

                MemoryContextStats(intset_ctx);
        }

        /* Check that intset_get_num_entries works */
        n = intset_num_entries(intset);
        if (n != spec->num_values)
                elog(ERROR, "intset_num_entries returned " UINT64_FORMAT ", expected " UINT64_FORMAT, n, spec->num_values);

        /*
         * Test random-access probes with intset_is_member()
         */
        starttime = GetCurrentTimestamp();

        for (n = 0; n < 100000; n++)
        {
                bool            b;
                bool            expected;
                uint64          x;

                /*
                 * Pick next value to probe at random.  We limit the probes to the
                 * last integer that we added to the set, plus an arbitrary constant
                 * (1000).  There's no point in probing the whole 0 - 2^64 range, if
                 * only a small part of the integer space is used.  We would very
                 * rarely hit values that are actually in the set.
                 */
                x = pg_prng_uint64_range(&pg_global_prng_state, 0, last_int + 1000);

                /* Do we expect this value to be present in the set? */
                if (x >= last_int)
                        expected = false;
                else
                {
                        uint64          idx = x % spec->spacing;

                        if (idx >= patternlen)
                                expected = false;
                        else if (spec->pattern_str[idx] == '1')
                                expected = true;
                        else
                                expected = false;
                }

                /* Is it present according to intset_is_member() ? */
                b = intset_is_member(intset, x);

                if (b != expected)
                        elog(ERROR, "mismatch at " UINT64_FORMAT ": %d vs %d", x, b, expected);
        }
        endtime = GetCurrentTimestamp();
        if (intset_test_stats)
                fprintf(stderr, "probed " UINT64_FORMAT " values in %d ms\n",
                                n, (int) (endtime - starttime) / 1000);

        /*
         * Test iterator
         */
        starttime = GetCurrentTimestamp();

        intset_begin_iterate(intset);
        n = 0;
        last_int = 0;
        while (n < spec->num_values)
        {
                for (int i = 0; i < pattern_num_values && n < spec->num_values; i++)
                {
                        uint64          expected = last_int + pattern_values[i];
                        uint64          x;

                        if (!intset_iterate_next(intset, &x))
                                break;

                        if (x != expected)
                                elog(ERROR, "iterate returned wrong value; got " UINT64_FORMAT ", expected " UINT64_FORMAT, x, expected);
                        n++;
                }
                last_int += spec->spacing;
        }
        endtime = GetCurrentTimestamp();
        if (intset_test_stats)
                fprintf(stderr, "iterated " UINT64_FORMAT " values in %d ms\n",
                                n, (int) (endtime - starttime) / 1000);

        if (n < spec->num_values)
                elog(ERROR, "iterator stopped short after " UINT64_FORMAT " entries, expected " UINT64_FORMAT, n, spec->num_values);
        if (n > spec->num_values)
                elog(ERROR, "iterator returned " UINT64_FORMAT " entries, " UINT64_FORMAT " was expected", n, spec->num_values);

        MemoryContextDelete(intset_ctx);
}

/*
 * Test with a set containing a single integer.
 */
static void
test_single_value(uint64 value)
{
        IntegerSet *intset;
        uint64          x;
        uint64          num_entries;
        bool            found;

        elog(NOTICE, "testing intset with single value " UINT64_FORMAT, value);

        /* Create the set. */
        intset = intset_create();
        intset_add_member(intset, value);

        /* Test intset_get_num_entries() */
        num_entries = intset_num_entries(intset);
        if (num_entries != 1)
                elog(ERROR, "intset_num_entries returned " UINT64_FORMAT ", expected 1", num_entries);

        /*
         * Test intset_is_member() at various special values, like 0 and maximum
         * possible 64-bit integer, as well as the value itself.
         */
        if (intset_is_member(intset, 0) != (value == 0))
                elog(ERROR, "intset_is_member failed for 0");
        if (intset_is_member(intset, 1) != (value == 1))
                elog(ERROR, "intset_is_member failed for 1");
        if (intset_is_member(intset, PG_UINT64_MAX) != (value == PG_UINT64_MAX))
                elog(ERROR, "intset_is_member failed for PG_UINT64_MAX");
        if (intset_is_member(intset, value) != true)
                elog(ERROR, "intset_is_member failed for the tested value");

        /*
         * Test iterator
         */
        intset_begin_iterate(intset);
        found = intset_iterate_next(intset, &x);
        if (!found || x != value)
                elog(ERROR, "intset_iterate_next failed for " UINT64_FORMAT, x);

        found = intset_iterate_next(intset, &x);
        if (found)
                elog(ERROR, "intset_iterate_next failed " UINT64_FORMAT, x);
}

/*
 * Test with an integer set that contains:
 *
 * - a given single 'value', and
 * - all integers between 'filler_min' and 'filler_max'.
 *
 * This exercises different codepaths than testing just with a single value,
 * because the implementation buffers newly-added values.  If we add just a
 * single value to the set, we won't test the internal B-tree code at all,
 * just the code that deals with the buffer.
 */
static void
test_single_value_and_filler(uint64 value, uint64 filler_min, uint64 filler_max)
{
        IntegerSet *intset;
        uint64          x;
        bool            found;
        uint64     *iter_expected;
        uint64          n = 0;
        uint64          num_entries = 0;
        uint64          mem_usage;

        elog(NOTICE, "testing intset with value " UINT64_FORMAT ", and all between " UINT64_FORMAT " and " UINT64_FORMAT,
                 value, filler_min, filler_max);

        intset = intset_create();

        iter_expected = palloc(sizeof(uint64) * (filler_max - filler_min + 1));
        if (value < filler_min)
        {
                intset_add_member(intset, value);
                iter_expected[n++] = value;
        }

        for (x = filler_min; x < filler_max; x++)
        {
                intset_add_member(intset, x);
                iter_expected[n++] = x;
        }

        if (value >= filler_max)
        {
                intset_add_member(intset, value);
                iter_expected[n++] = value;
        }

        /* Test intset_get_num_entries() */
        num_entries = intset_num_entries(intset);
        if (num_entries != n)
                elog(ERROR, "intset_num_entries returned " UINT64_FORMAT ", expected " UINT64_FORMAT, num_entries, n);

        /*
         * Test intset_is_member() at various spots, at and around the values that
         * we expect to be set, as well as 0 and the maximum possible value.
         */
        check_with_filler(intset, 0,
                                          value, filler_min, filler_max);
        check_with_filler(intset, 1,
                                          value, filler_min, filler_max);
        check_with_filler(intset, filler_min - 1,
                                          value, filler_min, filler_max);
        check_with_filler(intset, filler_min,
                                          value, filler_min, filler_max);
        check_with_filler(intset, filler_min + 1,
                                          value, filler_min, filler_max);
        check_with_filler(intset, value - 1,
                                          value, filler_min, filler_max);
        check_with_filler(intset, value,
                                          value, filler_min, filler_max);
        check_with_filler(intset, value + 1,
                                          value, filler_min, filler_max);
        check_with_filler(intset, filler_max - 1,
                                          value, filler_min, filler_max);
        check_with_filler(intset, filler_max,
                                          value, filler_min, filler_max);
        check_with_filler(intset, filler_max + 1,
                                          value, filler_min, filler_max);
        check_with_filler(intset, PG_UINT64_MAX - 1,
                                          value, filler_min, filler_max);
        check_with_filler(intset, PG_UINT64_MAX,
                                          value, filler_min, filler_max);

        intset_begin_iterate(intset);
        for (uint64 i = 0; i < n; i++)
        {
                found = intset_iterate_next(intset, &x);
                if (!found || x != iter_expected[i])
                        elog(ERROR, "intset_iterate_next failed for " UINT64_FORMAT, x);
        }
        found = intset_iterate_next(intset, &x);
        if (found)
                elog(ERROR, "intset_iterate_next failed " UINT64_FORMAT, x);

        mem_usage = intset_memory_usage(intset);
        if (mem_usage < 5000 || mem_usage > 500000000)
                elog(ERROR, "intset_memory_usage() reported suspicious value: " UINT64_FORMAT, mem_usage);
}

/*
 * Helper function for test_single_value_and_filler.
 *
 * Calls intset_is_member() for value 'x', and checks that the result is what
 * we expect.
 */
static void
check_with_filler(IntegerSet *intset, uint64 x,
                                  uint64 value, uint64 filler_min, uint64 filler_max)
{
        bool            expected;
        bool            actual;

        expected = (x == value || (filler_min <= x && x < filler_max));

        actual = intset_is_member(intset, x);

        if (actual != expected)
                elog(ERROR, "intset_is_member failed for " UINT64_FORMAT, x);
}

/*
 * Test empty set
 */
static void
test_empty(void)
{
        IntegerSet *intset;
        uint64          x;

        elog(NOTICE, "testing intset with empty set");

        intset = intset_create();

        /* Test intset_is_member() */
        if (intset_is_member(intset, 0) != false)
                elog(ERROR, "intset_is_member on empty set returned true");
        if (intset_is_member(intset, 1) != false)
                elog(ERROR, "intset_is_member on empty set returned true");
        if (intset_is_member(intset, PG_UINT64_MAX) != false)
                elog(ERROR, "intset_is_member on empty set returned true");

        /* Test iterator */
        intset_begin_iterate(intset);
        if (intset_iterate_next(intset, &x))
                elog(ERROR, "intset_iterate_next on empty set returned a value (" UINT64_FORMAT ")", x);
}

/*
 * Test with integers that are more than 2^60 apart.
 *
 * The Simple-8b encoding used by the set implementation can only encode
 * values up to 2^60.  That makes large differences like this interesting
 * to test.
 */
static void
test_huge_distances(void)
{
        IntegerSet *intset;
        uint64          values[1000];
        int                     num_values = 0;
        uint64          val = 0;
        bool            found;
        uint64          x;

        elog(NOTICE, "testing intset with distances > 2^60 between values");

        val = 0;
        values[num_values++] = val;

        /* Test differences on both sides of the 2^60 boundary. */
        val += UINT64CONST(1152921504606846976) - 1;    /* 2^60 - 1 */
        values[num_values++] = val;

        val += UINT64CONST(1152921504606846976) - 1;    /* 2^60 - 1 */
        values[num_values++] = val;

        val += UINT64CONST(1152921504606846976);        /* 2^60 */
        values[num_values++] = val;

        val += UINT64CONST(1152921504606846976);        /* 2^60 */
        values[num_values++] = val;

        val += UINT64CONST(1152921504606846976);        /* 2^60 */
        values[num_values++] = val;

        val += UINT64CONST(1152921504606846976) + 1;    /* 2^60 + 1 */
        values[num_values++] = val;

        val += UINT64CONST(1152921504606846976) + 1;    /* 2^60 + 1 */
        values[num_values++] = val;

        val += UINT64CONST(1152921504606846976) + 1;    /* 2^60 + 1 */
        values[num_values++] = val;

        val += UINT64CONST(1152921504606846976) + 2;    /* 2^60 + 2 */
        values[num_values++] = val;

        val += UINT64CONST(1152921504606846976) + 2;    /* 2^60 + 2 */
        values[num_values++] = val;

        val += UINT64CONST(1152921504606846976);        /* 2^60 */
        values[num_values++] = val;

        /*
         * We're now very close to 2^64, so can't add large values anymore.  But
         * add more smaller values to the end, to make sure that all the above
         * values get flushed and packed into the tree structure.
         */
        while (num_values < 1000)
        {
                val += pg_prng_uint32(&pg_global_prng_state);
                values[num_values++] = val;
        }

        /* Create an IntegerSet using these values */
        intset = intset_create();
        for (int i = 0; i < num_values; i++)
                intset_add_member(intset, values[i]);

        /*
         * Test intset_is_member() around each of these values
         */
        for (int i = 0; i < num_values; i++)
        {
                uint64          y = values[i];
                bool            expected;
                bool            result;

                if (y > 0)
                {
                        expected = (values[i - 1] == y - 1);
                        result = intset_is_member(intset, y - 1);
                        if (result != expected)
                                elog(ERROR, "intset_is_member failed for " UINT64_FORMAT, y - 1);
                }

                result = intset_is_member(intset, y);
                if (result != true)
                        elog(ERROR, "intset_is_member failed for " UINT64_FORMAT, y);

                expected = (i != num_values - 1) ? (values[i + 1] == y + 1) : false;
                result = intset_is_member(intset, y + 1);
                if (result != expected)
                        elog(ERROR, "intset_is_member failed for " UINT64_FORMAT, y + 1);
        }

        /*
         * Test iterator
         */
        intset_begin_iterate(intset);
        for (int i = 0; i < num_values; i++)
        {
                found = intset_iterate_next(intset, &x);
                if (!found || x != values[i])
                        elog(ERROR, "intset_iterate_next failed for " UINT64_FORMAT, x);
        }
        found = intset_iterate_next(intset, &x);
        if (found)
                elog(ERROR, "intset_iterate_next failed " UINT64_FORMAT, x);
}