Hello Alvaro,
I read the whole thread, I still don't know what this patch is supposed to
do. I know what the words in the subject line mean, but I don't know how
this helps a pgbench user run better benchmarks. I feel this is also the
sentiment expressed by others earlier in the thread. You indicated that
this functionality makes sense to those who want this functionality, but so
far only two people, namely the patch author and the reviewer, have
participated in the discussion on the substance of this patch. So either
the feature is extremely niche, or nobody understands it. I think you ought
to take about three steps back and explain this in more basic terms, even
just in email at first so that we can then discuss what to put into the
documentation.
After re-reading one more time, it dawned on me that the point of this
is similar in spirit to this one:
https://wiki.postgresql.org/wiki/Pseudo_encrypt
Indeed. The one in the wiki is useless because it is on all integers,
whereas in a benchmark you want it for a given size and you want seeding,
but otherwise the same correlation-avoidance problem is addressed.
The idea seems to be to map the int4 domain into itself, so you can use
a sequence to generate numbers that will not look like a sequence,
allowing the user to hide some properties (such as the generation rate)
that might be useful to an eavesdropper/attacker. In terms of writing
benchmarks, it seems useful to destroy all locality of access, which
changes the benchmark completely.
Yes.
(I'm not sure if this is something benchmark writers really want to
have.)
I do not get this sentence. I'm sure that a benchmark writer should really
want to avoid unrealistic correlations that have a performance impact.
If I'm right, then I agree that the documentation provided with the
patch does a pretty bad job at explaining it, because until now I didn't
at all realize this is what it was.
The documentation is improvable, no doubt.
Attached is an attempt at improving things. I have added a explicit note
and hijacked an existing example to better illustrate the purpose of the
function.
--
Fabien.
diff --git a/doc/src/sgml/ref/pgbench.sgml b/doc/src/sgml/ref/pgbench.sgml
index 4c48a58ed2..d2344b029b 100644
--- a/doc/src/sgml/ref/pgbench.sgml
+++ b/doc/src/sgml/ref/pgbench.sgml
@@ -998,7 +998,7 @@ pgbench <optional> <replaceable>options</replaceable> </optional> <replaceable>d
<row>
<entry> <literal>default_seed</literal> </entry>
- <entry>seed used in hash functions by default</entry>
+ <entry>seed used in hash and pseudo-random permutation functions by default</entry>
</row>
<row>
@@ -1494,6 +1494,13 @@ SELECT 2 AS two, 3 AS three \gset p_
<entry><literal>pow(2.0, 10)</literal>, <literal>power(2.0, 10)</literal></entry>
<entry><literal>1024.0</literal></entry>
</row>
+ <row>
+ <entry><literal><function>pr_perm(<replaceable>i</replaceable>, <replaceable>size</replaceable> [, <replaceable>seed</replaceable> ] )</function></literal></entry>
+ <entry>integer</entry>
+ <entry>pseudo-random permutation in [0,size)</entry>
+ <entry><literal>pr_perm(0, 4)</literal></entry>
+ <entry><literal>0</literal>, <literal>1</literal>, <literal>2</literal> or <literal>3</literal></entry>
+ </row>
<row>
<entry><literal><function>random(<replaceable>lb</replaceable>, <replaceable>ub</replaceable>)</function></literal></entry>
<entry>integer</entry>
@@ -1545,6 +1552,20 @@ SELECT 2 AS two, 3 AS three \gset p_
shape of the distribution.
</para>
+ <note>
+ <para>
+ When designing a benchmark which selects rows non-uniformly, be aware
+ that using <application>pgbench</application> non-uniform random functions
+ directly leads to unduly correlations: rows with close ids come out with
+ similar probability, skewing performance measures because they also reside
+ in close pages.
+ </para>
+ <para>
+ You must use <function>pr_perm</function> to shuffle the selected ids, or
+ some other additional step with similar effect, to avoid these skewing impacts.
+ </para>
+ </note>
+
<itemizedlist>
<listitem>
<para>
@@ -1639,24 +1660,54 @@ f(x) = PHI(2.0 * parameter * (x - mu) / (max - min + 1)) /
<literal>hash_fnv1a</literal> accept an input value and an optional seed parameter.
In case the seed isn't provided the value of <literal>:default_seed</literal>
is used, which is initialized randomly unless set by the command-line
- <literal>-D</literal> option. Hash functions can be used to scatter the
- distribution of random functions such as <literal>random_zipfian</literal> or
- <literal>random_exponential</literal>. For instance, the following pgbench
- script simulates possible real world workload typical for social media and
+ <literal>-D</literal> option.
+ </para>
+
+ <para>
+ Function <literal>pr_perm</literal> implements a pseudo-random permutation
+ on an arbitrary size.
+ It allows to shuffle output of non uniform random functions so that
+ values drawn more often are not trivially correlated.
+ It permutes integers in [0, size) using a seed by applying rounds of
+ simple invertible functions, similarly to an encryption function,
+ although beware that it is not at all cryptographically secure.
+ Compared to <literal>hash</literal> functions discussed above, the function
+ ensures that a perfect permutation is applied: there are neither collisions
+ nor holes in the output values.
+ Values outside the interval are interpreted modulo the size.
+ The function raises an error if size is not positive.
+ If no seed is provided, <literal>:default_seed</literal> is used.
+
+ For instance, the following <application>pgbench</application> script
+ simulates possible real world workload typical for social media and
blogging platforms where few accounts generate excessive load:
<programlisting>
-\set r random_zipfian(0, 100000000, 1.07)
-\set k abs(hash(:r)) % 1000000
+\set size 1000000
+\set r random_zipfian(1, :size, 1.07)
+\set k 1 + pr_perm(:r, :size)
</programlisting>
In some cases several distinct distributions are needed which don't correlate
with each other and this is when implicit seed parameter comes in handy:
<programlisting>
-\set k1 abs(hash(:r, :default_seed + 123)) % 1000000
-\set k2 abs(hash(:r, :default_seed + 321)) % 1000000
+\set k1 1 + pr_perm(:r, :size, :default_seed + 123)
+\set k2 1 + pr_perm(:r, :size, :default_seed + 321)
</programlisting>
+
+ An similar behavior can also be approximated with
+ <function>hash</function>:
+
+<programlisting>
+\set size 1000000
+\set r random_zipfian(1, 100 * :size, 1.07)
+\set k 1 + abs(hash(:r)) % :size
+</programlisting>
+
+ As this hash-modulo version generates collisions, some
+ <literal>id</literal> would not be reachable and others would come more often
+ than the target distribution.
</para>
<para>
diff --git a/src/bin/pgbench/exprparse.y b/src/bin/pgbench/exprparse.y
index 85d61caa9f..0ea968c94b 100644
--- a/src/bin/pgbench/exprparse.y
+++ b/src/bin/pgbench/exprparse.y
@@ -19,6 +19,7 @@
#define PGBENCH_NARGS_VARIABLE (-1)
#define PGBENCH_NARGS_CASE (-2)
#define PGBENCH_NARGS_HASH (-3)
+#define PGBENCH_NARGS_PRPERM (-4)
PgBenchExpr *expr_parse_result;
@@ -370,6 +371,9 @@ static const struct
{
"hash_fnv1a", PGBENCH_NARGS_HASH, PGBENCH_HASH_FNV1A
},
+ {
+ "pr_perm", PGBENCH_NARGS_PRPERM, PGBENCH_PRPERM
+ },
/* keep as last array element */
{
NULL, 0, 0
@@ -482,6 +486,19 @@ make_func(yyscan_t yyscanner, int fnumber, PgBenchExprList *args)
}
break;
+ /* pseudo-random permutation function with optional seed argument */
+ case PGBENCH_NARGS_PRPERM:
+ if (len < 2 || len > 3)
+ expr_yyerror_more(yyscanner, "unexpected number of arguments",
+ PGBENCH_FUNCTIONS[fnumber].fname);
+
+ if (len == 2)
+ {
+ PgBenchExpr *var = make_variable("default_seed");
+ args = make_elist(var, args);
+ }
+ break;
+
/* common case: positive arguments number */
default:
Assert(PGBENCH_FUNCTIONS[fnumber].nargs >= 0);
diff --git a/src/bin/pgbench/pgbench.c b/src/bin/pgbench/pgbench.c
index 39c1a243d5..3df863e95f 100644
--- a/src/bin/pgbench/pgbench.c
+++ b/src/bin/pgbench/pgbench.c
@@ -32,6 +32,13 @@
#endif
#include "postgres_fe.h"
+#include "common/int.h"
+#include "common/logging.h"
+#include "fe_utils/conditional.h"
+#include "getopt_long.h"
+#include "libpq-fe.h"
+#include "portability/instr_time.h"
+#include "port/pg_bitutils.h"
#include <ctype.h>
#include <float.h>
@@ -1057,6 +1064,319 @@ getHashMurmur2(int64 val, uint64 seed)
return (int64) result;
}
+/* pseudo-random permutation */
+
+/* 16 so that % 16 can be optimized to & 0x0f */
+#define PRP_PRIMES 16
+/*
+ * 24 bit mega primes from https://primes.utm.edu/lists/small/millions/
+ * the i-th prime, i \in [0, 15], is the first prime above 2^23 + i * 2^19
+ */
+static uint64 primes[PRP_PRIMES] = {
+ UINT64CONST(8388617),
+ UINT64CONST(8912921),
+ UINT64CONST(9437189),
+ UINT64CONST(9961487),
+ UINT64CONST(10485767),
+ UINT64CONST(11010059),
+ UINT64CONST(11534351),
+ UINT64CONST(12058679),
+ UINT64CONST(12582917),
+ UINT64CONST(13107229),
+ UINT64CONST(13631489),
+ UINT64CONST(14155777),
+ UINT64CONST(14680067),
+ UINT64CONST(15204391),
+ UINT64CONST(15728681),
+ UINT64CONST(16252967)
+};
+
+/* how many "encryption" rounds to apply */
+#define PRP_ROUNDS 4
+
+/* return smallest mask holding n */
+static uint64
+compute_mask(uint64 n)
+{
+ n |= n >> 1;
+ n |= n >> 2;
+ n |= n >> 4;
+ n |= n >> 8;
+ n |= n >> 16;
+ n |= n >> 32;
+ return n;
+}
+
+#if !defined(PG_INT128_TYPE)
+/* length of n binary representation */
+static int
+nbits(uint64 n)
+{
+ /* set lower bits to 1 and count them */
+ return pg_popcount64(compute_mask(n));
+}
+#endif
+
+#define HIBITS UINT64CONST(0xffffffff00000000)
+#define LOBITS UINT64CONST(0x00000000ffffffff)
+
+static uint64
+modular_multiply_2(const uint64 x, const uint64 y, const uint64 m)
+{
+ /* x = x1 2^32 + x0 with x0 and x1 32 bits */
+ uint64 x1 = (x & HIBITS) >> 32, x0 = x & LOBITS;
+ uint64 y1 = (y & HIBITS) >> 32, y0 = y & LOBITS;
+
+}
+
+/*
+ * Compute (x * y) % m, where x and y in [0, 2^64), m in [1, 2^64).
+ *
+ * Use improved interleaved modular multiplication algorithm to avoid
+ * overflows when necessary.
+ */
+static uint64
+modular_multiply(uint64 x, uint64 y, const uint64 m)
+{
+#if defined(PG_INT128_TYPE)
+ return (PG_INT128_TYPE) x * (PG_INT128_TYPE) y % (PG_INT128_TYPE) m;
+#else
+ int i,
+ bits;
+ uint64 r;
+
+ Assert(m >= 1);
+
+ /* Because of (x * y) % m = (x % m * y % m) % m */
+ if (x >= m)
+ x %= m;
+ if (y >= m)
+ y %= m;
+
+ /* Return the trivial result. */
+ if (x == 0 || y == 0 || m == 1)
+ return 0;
+
+ /* Return the result if (x * y) can be multiplied without overflow. */
+ if (nbits(x) + nbits(y) <= 64)
+ return (x * y) % m;
+
+ /* To reduce the for loop in the algorithm below, ensure y <= x. */
+ if (x < y)
+ {
+ uint64 tmp = x;
+
+ x = y;
+ y = tmp;
+ }
+
+ /*-----
+ * Interleaved modular multiplication algorithm from:
+ *
+ * D.N. Amanor et al., "Efficient hardware architecture for modular
+ * multiplication on FPGAs", in International Conference on Field
+ * Programmable Logic and Applications, Aug 2005, pp. 539-542.
+ *
+ * This algorithm is usually used in the field of digital circuit design.
+ *
+ * Input: X, Y, M; 0 <= X, Y <= M;
+ * Output: R = X * Y mod M;
+ * bits: number of bits of Y
+ * Y[i]: i th bit of Y
+ *
+ * 1. R = 0;
+ * 2. for (i = bits - 1; i >= 0; i--) {
+ * 3. R = 2 * R;
+ * 4. if (Y[i] == 0x1)
+ * 5. R += X;
+ * 6. if (R >= M) R -= M;
+ * 7. if (R >= M) R -= M;
+ * }
+ *
+ * In Steps 3 and 5, overflow should be avoided. The details are explained
+ * in each step.
+ * Steps 6 and 7 can be instead a modular operation (R %= M).
+ *
+ * Note that, in this implementation, the distributive property of modular
+ * operation shown in below is used whenever it can be applied.
+ * (X * Y) % M = X % M * Y % M, (X + Y) % M = X % M + Y % M
+ *
+ * For ease of understanding, an example is shown.
+ * Example: (11 * 5) % 7
+ *
+ * [Notation] ":=" means substitution.
+ *
+ * [initial value]
+ * R := 0x0000
+ *
+ * [i=2]
+ * R := (0x0000 * 2) % 0x0111 = 0x0000
+ * R := (R + 0x1011) % 0x0111 = 0x0100
+ *
+ * [i=1]
+ * R := (0x0100 * 2) % 0x0111 = 0x1000 % 0x0111 = 0x0001
+ *
+ * [i=0]
+ * R := (0x0001 * 2) % 0x0111 = 0x0010
+ * R := (R + 0x1011) % 0x0111 = 0x1101 % 0x0111 = 0x0110
+ *
+ * [result]
+ * R = 6
+ */
+
+ bits = nbits(y);
+ r = 0;
+
+ for (i = bits - 1; i >= 0; i--)
+ {
+ if (r > UINT64CONST(0x7fffffffffffffff))
+ /*-----
+ * To avoid overflow, transform from (2 * r) to (2 * r) % m, and
+ * further transform to mathematically equivalent form below:
+ *
+ * For ease of understanding, an example using one digit decimal number,
+ * where r = 6 and m = 7, is shown.
+ * (6 * 2) % 7 = (7 - 1) * 2 % 7 = (7 % 7 - 1 % 7) * 2 % 7
+ * = (0 - 1) * 2 % 7 = -2 % 7 = 7 - 2 = 5.
+ * Generally, if (r * 2) overflows,
+ * (r * 2) % m = m - (m - r) * 2.
+ */
+ r = m - ((m - r) << 1);
+ else
+ r <<= 1;
+
+ if ((y >> i) & 0x1)
+ {
+ if (r > UINT64CONST(0xffffffffffffffff) - x)
+ /*-----
+ * To compute (r + x) without overflow: transform to
+ * (r + x) % m, and then to (r + x - m).
+ *
+ * An example using one digit decimal number, where r = 6, x = 5 and
+ * m = 7, is shown.
+ * (6 + 5) % 7 = (6 + (5 - 7 + 7)) % 7 = 6 % 7 + (5 - 7) % 7 + 7 % 7
+ * = 6 + (5 - 7) + 0 = 4.
+ * Generally, if (r + x) overflows,
+ * (r + x) % m = r + (x - m).
+ */
+ r += x - m;
+ else
+ r += x;
+ }
+
+ r %= m;
+ }
+
+ return r;
+#endif
+}
+
+/*
+ * Donald Knuth's linear congruential generator
+ *
+ * Relying on multiplication overflows is part of the design
+ * of this simple pseudo random number generator.
+ */
+#define DK_LCG_MUL UINT64CONST(6364136223846793005)
+#define DK_LCG_INC UINT64CONST(1442695040888963407)
+
+/* do not use all small bits */
+#define LCG_SHIFT 13
+
+/*
+ * PRP: parametric pseudo-random permutation
+ *
+ * Result in [0, size) is a permutation for inputs in the same set.
+ *
+ * Note that this function does not pass statistical tests: eg
+ * permutations of 2, 3, 4 or 5 ints are not strictly equiprobable.
+ * Things worsen for large sizes as there are many more permutations
+ * (size!) than seeds to select them (2^64 < 21!).
+ * However it is inexpensive compared to an actual encryption function,
+ * and the quality is good enough to avoid trivial correlations on
+ * large sizes, which is the expected use case.
+ *
+ * THIS FUNCTION IS NOT CRYPTOGRAPHICALLY SECURE.
+ * DO NOT USE FOR SUCH PURPOSE.
+ */
+static int64
+pseudorandom_perm(const int64 data, const int64 isize, const int64 seed)
+{
+ /* computations are performed on unsigned values */
+ uint64 size = (uint64) isize;
+ uint64 v = (uint64) data % size;
+ uint64 key = (uint64) seed;
+ /* size-1 ensures 2 possibly overlapping halves */
+ uint64 mask = compute_mask(size - 1) >> 1;
+
+ /* nothing to permute */
+ if (isize == 1)
+ return 0;
+
+ Assert(isize >= 2);
+
+ /*-----
+ * Apply 4 rounds of bijective transformations using key updated
+ * at each stage:
+ *
+ * (1) scramble: partial xors on overlapping power-of-2 subsets
+ * for instance with v in 0 .. 14 (i.e. with size == 15):
+ * if v is in 0 .. 7 do v = (v ^ k) % 8
+ * if v is in 7 .. 14 do v = 14 - ((14-v) ^ k) % 8
+ * note that because of the overlap (here 7), v may be changed twice.
+ * this transformation if bijective because the condition to apply it
+ * is still true after applying it, and xor itself is bijective on a
+ * power-of-2 size.
+ *
+ * (2) scatter: linear modulo
+ * v = (v * p + k) % size
+ * this transformation is bijective is p & size are prime, which is
+ * ensured in the code by the while loop which discards primes when
+ * size is a multiple of it.
+ *
+ */
+ for (unsigned int i = 0, p = key % PRP_PRIMES; i < PRP_ROUNDS; i++, p = (p + 1) % PRP_PRIMES)
+ {
+ uint64 t;
+
+ /* first "half" whitening, for v in 0 .. mask */
+ key = key * DK_LCG_MUL + DK_LCG_INC;
+ if (v <= mask)
+ v ^= (key >> LCG_SHIFT) & mask;
+
+ /* second (possibly overlapping) "half" whitening */
+ key = key * DK_LCG_MUL + DK_LCG_INC;
+ t = size - 1 - v;
+ if (t <= mask)
+ {
+ t ^= (key >> LCG_SHIFT) & mask;
+ v = size - 1 - t;
+ }
+
+ /* at most 2 primes are skipped for a given size */
+ while (unlikely(size % primes[p] == 0))
+ p = (p + 1) % PRP_PRIMES;
+
+ /* scatter values with a prime multiplication */
+ key = key * DK_LCG_MUL + DK_LCG_INC;
+
+ /* Performance shortcut for 24 bit primes, ok for size up to ~10E12 */
+ if ((v & UINT64CONST(0xffffffffff)) == v)
+ v = (primes[p] * v + (key >> LCG_SHIFT)) % size;
+ else
+ /*-----
+ * Note: the add cannot overflow as size is under 63 bits:
+ * mmv = mm(prime, v, size) < size <= 0x7fffffffffffffff = (1<<63)-1
+ * ks = key >> LCG_SHIFTS <= 2^51
+ * => mmv + ks < (1<<64) - 1
+ */
+ v = (modular_multiply(primes[p], v, size) + (key >> LCG_SHIFT)) % size;
+ }
+
+ /* back to signed */
+ return (int64) v;
+}
+
/*
* Initialize the given SimpleStats struct to all zeroes
*/
@@ -2394,6 +2714,27 @@ evalStandardFunc(CState *st,
return true;
}
+ case PGBENCH_PRPERM:
+ {
+ int64 val, size, seed;
+
+ Assert(nargs == 3);
+
+ if (!coerceToInt(&vargs[0], &val) ||
+ !coerceToInt(&vargs[1], &size) ||
+ !coerceToInt(&vargs[2], &seed))
+ return false;
+
+ if (size < 1)
+ {
+ fprintf(stderr, "pr_perm size parameter must be >= 1\n");
+ return false;
+ }
+
+ setIntValue(retval, pseudorandom_perm(val, size, seed));
+ return true;
+ }
+
default:
/* cannot get here */
Assert(0);
diff --git a/src/bin/pgbench/pgbench.h b/src/bin/pgbench/pgbench.h
index fb2c34f512..a95095a27d 100644
--- a/src/bin/pgbench/pgbench.h
+++ b/src/bin/pgbench/pgbench.h
@@ -99,7 +99,8 @@ typedef enum PgBenchFunction
PGBENCH_IS,
PGBENCH_CASE,
PGBENCH_HASH_FNV1A,
- PGBENCH_HASH_MURMUR2
+ PGBENCH_HASH_MURMUR2,
+ PGBENCH_PRPERM
} PgBenchFunction;
typedef struct PgBenchExpr PgBenchExpr;
diff --git a/src/bin/pgbench/t/001_pgbench_with_server.pl b/src/bin/pgbench/t/001_pgbench_with_server.pl
index 25ea17f7d1..c4d57221b7 100644
--- a/src/bin/pgbench/t/001_pgbench_with_server.pl
+++ b/src/bin/pgbench/t/001_pgbench_with_server.pl
@@ -384,6 +384,17 @@ pgbench(
qr{command=98.: int 5432\b}, # :random_seed
qr{command=99.: int -9223372036854775808\b}, # min int
qr{command=100.: int 9223372036854775807\b}, # max int
+ qr{command=101.: boolean true\b},
+ qr{command=102.: boolean true\b},
+ qr{command=103.: boolean true\b},
+ qr{command=104.: boolean true\b},
+ qr{command=105.: boolean true\b},
+ qr{command=109.: boolean true\b},
+ qr{command=110.: boolean true\b},
+ qr{command=111.: boolean true\b},
+ qr{command=112.: boolean true\b},
+ qr{command=113.: int 9223372036854775797\b},
+ qr{command=114.: boolean true\b},
],
'pgbench expressions',
{
@@ -511,6 +522,37 @@ SELECT :v0, :v1, :v2, :v3;
-- minint constant parsing
\set min debug(-9223372036854775808)
\set max debug(-(:min + 1))
+-- pseudo-random permutation
+\set t debug(pr_perm(0, 2) + pr_perm(1, 2) = 1)
+\set t debug(pr_perm(0, 3) + pr_perm(1, 3) + pr_perm(2, 3) = 3)
+\set t debug(pr_perm(0, 4) + pr_perm(1, 4) + pr_perm(2, 4) + pr_perm(3, 4) = 6)
+\set t debug(pr_perm(0, 5) + pr_perm(1, 5) + pr_perm(2, 5) + pr_perm(3, 5) + pr_perm(4, 5) = 10)
+\set t debug(pr_perm(0, 16) + pr_perm(1, 16) + pr_perm(2, 16) + pr_perm(3, 16) + \
+ pr_perm(4, 16) + pr_perm(5, 16) + pr_perm(6, 16) + pr_perm(7, 16) + \
+ pr_perm(8, 16) + pr_perm(9, 16) + pr_perm(10, 16) + pr_perm(11, 16) + \
+ pr_perm(12, 16) + pr_perm(13, 16) + pr_perm(14, 16) + pr_perm(15, 16) = 120)
+-- random sanity check
+\set size random(2, 1000)
+\set v random(0, :size - 1)
+\set p pr_perm(:v, :size)
+\set t debug(0 <= :p and :p < :size and :p = pr_perm(:v + :size, :size) and :p <> pr_perm(:v + 1, :size))
+-- actual values
+\set t debug(pr_perm(:v, 1) = 0)
+\set t debug(pr_perm(0, 2, 5432) = 0 and pr_perm(1, 2, 5432) = 1 and \
+ pr_perm(0, 2, 5431) = 1 and pr_perm(1, 2, 5431) = 0)
+-- ~50 bits test to exercise full modular multiplication
+\set t debug(pr_perm(0, 1000000000000000, 54321) = 9406454989259 and \
+ pr_perm(1999999999999999, 1000000000000000, 54321) = 54570773902028 and \
+ pr_perm(2500000000000000, 1000000000000000, 54321) = 771082311307468)
+-- 63 bits tests
+\set size debug(:max - 10)
+\set ok debug(pr_perm(:size-1, :size, 5432) = 7214172101785397543 and \
+ pr_perm(:size-2, :size, 5432) = 4060085360303920649 and \
+ pr_perm(:size-3, :size, 5432) = 919477102797071521 and \
+ pr_perm(:size-4, :size, 5432) = 7588404289602340497 and \
+ pr_perm(:size-5, :size, 5432) = 5568354808723584469 and \
+ pr_perm(:size-6, :size, 5432) = 2410458883211907565 and \
+ pr_perm(:size-7, :size, 5432) = 1738667467693569814)
}
});
@@ -824,9 +866,13 @@ SELECT LEAST(} . join(', ', (':i') x 256) . q{)}
],
[ 'misc empty script', 1, [qr{empty command list for script}], q{} ],
[
- 'bad boolean', 2,
+ 'bad boolean', 2,
[qr{malformed variable.*trueXXX}], q{\set b :badtrue or true}
],
+ [
+ 'invalid pr_perm size', 2,
+ [qr{pr_perm size parameter must be >= 1}], q{\set i pr_perm(0, 0)}
+ ],
# GSET
[
diff --git a/src/bin/pgbench/t/002_pgbench_no_server.pl b/src/bin/pgbench/t/002_pgbench_no_server.pl
index 66b1bd6ff6..afd40b11f3 100644
--- a/src/bin/pgbench/t/002_pgbench_no_server.pl
+++ b/src/bin/pgbench/t/002_pgbench_no_server.pl
@@ -328,6 +328,16 @@ my @script_tests = (
'set i',
[ qr{set i 1 }, qr{\^ error found here} ],
{ 'set_i_op' => "\\set i 1 +\n" }
+ ],
+ [
+ 'not enough arguments for pr_perm',
+ [qr{unexpected number of arguments \(pr_perm\)}],
+ { 'bad-pr_perm-1.sql' => "\\set i pr_perm(1)\n" }
+ ],
+ [
+ 'too many arguments for pr_perm',
+ [qr{unexpected number of arguments \(pr_perm\)}],
+ { 'bad-pr_perm-2.sql' => "\\set i pr_perm(1, 2, 3, 4)\n" }
],);
for my $t (@script_tests)
