Postgres Benchmarks

This is a collection of quick-and-dirty benchmarks of Postgres that I wrote while investigating the performance of "schemaless" types (HSTORE, JSON, JSONB), and variable-length substring matching with BYTEA and TEXT. I wrote two blog posts about them:

Running the benchmarks

The .sql files contain the scripts I used to run the benchmarks. I ran each one like:

psql --file=perf_hstore.sql 'postgresql://postgres@/?host=...' | tee perf_hstore.sql.out

The .out files contain the raw output from running the tests.

I also wrote generate_payloads.py to help me generate the appropriate payloads. The output from that was unfortunately heavily edited, so it may not be directly useful.

Raw results

I also copy/pasted the results into a Google Sheet: https://docs.google.com/spreadsheets/d/1WVQuxnZbQrUfg0MWQ7TtDag0sx7to1j4xMik2E11yIQ/edit?usp=sharing

Hstore inline uncompressed

10 k/v pairs, 96 byte key, 96 byte value = 1920 data bytes
column size 2008
tuple size 2032
table pages 250000
pg_total_relation_size 2048598016 | 1954 MB
select found: 595 ms
select not found: 554 ms
count found: 588
count not found: 553

Hstore inline compressed

10 k/v pairs, 96 byte key, 96 byte value + 1 byte = 1921 data bytes
column size 200
tuple size 224
table pages 28572
pg_total_relation_size 234160128 | 223 MB
select found: 1120.415
select not found: 1098.878
count found: 1116.332
count not found: 1080.118

Hstore toast uncompressed

10 k/v pairs, 96 byte key, 96 byte value + 1 byte = 1921 data bytes
column size 2005
tuple size 2033
table pages: 6370
toast pages: 333334
toast tuples: 2000000 (2 toast tuples per value)
pg_total_relation_size: 2828615680 | 2698 MB
select found: 3494
select not found: 3438
count found: 3537
count not found: 3437

Hstore toast compressed

smallest compressed toast: constructed by hand to be compressed, but just too large to be stored inline
10 k/v pairs, 96 byte key, 7 with 193 byte values, 1 with 103 byte value, 1 with 96 byte value, 1 with 97 byte value = 2607 data bytes
column size 2006
tuple size 2034
table pages: 6370
toast pages: 333334
toast tuples: 2000000 (2 toast tuples per value)
pg_total_relation_size: 2828615680 | 2698 MB
select found: 7569
select not found: 7442
count found: 7544
count not found: 7454

Text inline uncompressed

2004 data bytes
column size 2008
tuple size 2032
table pages 250000
toast pages 0
pg_total_relation_size 2048598016 | 1954 MB
select v: 268 ms
select count(v): 289 ms
count() where not null: 411 ms
count() length > 100: 433 ms
count() length > 10000: 291 ms
count() not found like: 3218
count() found at end like: 3090
count() not found regexp: 11697
count() found at end regexp: 12442
count() not found position: 1562
count() found at end position: 5621

Text inline compressed

2005 data bytes
column size 44
tuple size 68
table pages 17680
toast pages 0
pg_total_relation_size 76619776 | 73 MB
select v: 115 ms
select count(v):
count() where not null query: 179 ms
count() length > 100 query: 183 ms
count() length > 10000 query: 87 ms
count() not found like: 2831
count() found at end like: 2919
count() not found regexp: 11476
count() found at end regexp: 12128
count() not found position: 3569
count() found at end position: 5631

Text toast uncompressed

column size 2005
tuple size 2033
table pages 6370
toast pages 333334
pg_total_relation_size 2828615680 | 2698 MB
select v: 117 ms
select count(v):
count() where not null query: 169 ms
count() length > 100 query: 175 ms
count() length > 10000 query: 82 ms
count() not found like: 6002
count() found at end like: 6069
count() not found regexp: 14574
count() found at end regexp: 15719
count() not found position: 4371
count() found at end position: 8574

Text toast compressed

Data bytes 2766
column size 2005
tuple size 2033
table pages 6370
toast pages 333334
pg_total_relation_size 2828615680 | 2698 MB
select v: 125 ms
select count(v):
count() where not null query: 178 ms
count() length > 100 query: 184 ms
count() length > 10000 query: 90 ms
count() not found like: 10681
count() found at end like: 10463
count() not found regexp: 22663
count() found at end regexp: 23359
count() not found position: 9547
count() found at end position: 14327

Bytea inline uncompressed

2004 data bytes
column size 2008
tuple size 2032
table pages 250000
toast pages 0
pg_total_relation_size 2048598016 | 1954 MB
select v: 237
select count(v): 260 ms
count() where not null: 352 ms
count() length > 100: 351 ms
count() length > 10000: 251 ms
count() not found like: 2317
count() found at end like: 2176
count() not found position: 2092
count() found at end position: 2067

Bytea inline compressed

2005 data bytes
column size 44
tuple size 68
table pages 17680
toast pages 0
pg_total_relation_size 76619776 | 73 MB
select v: 115 ms
select count(v):
count() where not null query: 173 ms
count() length > 100 query: 176 ms
count() length > 10000 query: 86 ms
count() not found like: 1714
count() found at end like: 1803
count() not found position: 1798
count() found at end position: 1897

Bytea toast uncompressed

column size 2005
tuple size 2033
table pages 6370
toast pages 333334
pg_total_relation_size 2828615680 | 2698 MB
select v: 115 ms
select count(v):
count() where not null query: 176 ms
count() length > 100 query: 178 ms
count() length > 10000 query: 85 ms
count() not found like: 5077
count() found at end like: 5095
count() not found position: 4933
count() found at end position: 5010

Bytea toast compressed

Data bytes 2766
column size 2005
tuple size 2033
table pages 6370
toast pages 333334
pg_total_relation_size 2828615680 | 2698 MB
select v: 114 ms
select count(v):
count() where not null query: 183 ms
count() length > 100 query: 178 ms
count() length > 10000 query: 86 ms
count() not found like: 9207
count() found at end like: 8959
count() not found position: 9088
count() found at end position: 9038

JSON inline uncompressed

10 k/v pairs; 96 byte key, 98 byte value + 3 = 1943 data bytes
column size 2008
tuple size 2032
table pages 250000
toast pages 0
pg_total_relation_size 2048598016 | 1954 MB
count found first: 10868
count found last: 10815
count not found: 10797

JSON inline compressed

10 k/v pairs; 96 byte key, 98 byte value + 4 = 1944 data bytes
column size 144
tuple size 168
table pages 21277
toast pages 0
pg_total_relation_size 174383104 | 166 MB
count found first: 11785
count found last: 11794
count not found: 11795

JSON toast uncompressed

10 k/v pairs; 96 byte key, 98 byte value + 4 = 1944 data bytes
column size 2005
tuple size 2033
table pages 6370
toast pages 333334
pg_total_relation_size 2828615680 | 2698 MB
count found first: 14156
count found last: 14220
count not found: 14011

JSON toast compressed

10 k/v pairs, 96 byte key, 187 byte value + 2 = 2832 data bytes
column size 2005
tuple size 2033
table pages 6370
toast pages 333334
pg_total_relation_size 2828615680 | 2698 MB
count found first: 22337
count found last: 22197
count not found: 22318

JSONB inline uncompressed

10 k/v pairs, 96 byte key 96 byte value = 1920 data bytes
column size 2008
tuple size 2032
table pages 250000
toast pages 0
pg_total_relation_size 2048598016 | 1954 MB
count found first ->: 976
count found first ->>: 875
count found last ->: 856
count not found ->: 746
In general ->> is slightly faster than ->
timing varies substantially between keys: from 770 to 650 ms

JSONB inline compressed

10 k/v pairs, 96 byte key, 96 byte value + 1 = 1921 data bytes
column size 117
tuple size 141
table pages 250000
toast pages 0
pg_total_relation_size 149020672 | 142 MB
count found first ->: 1334
count found last ->: 1337
count not found ->: 1178

JSONB toast uncompressed

10 k/v pairs, 96 byte key, 96 byte value + 1 = 1921 data bytes
column size 2005
tuple size 2033
table pages 250000
toast pages 0
pg_total_relation_size 2828615680 | 2698 MB
count found first ->: 3590
count found last ->: 3533
count not found ->: 3393

JSONB toast compressed

10 k/v pairs; 96 byte keys, 172 byte values + 1 = 2681 data bytes
column size 144
tuple size 168
table pages 250000
toast pages 0
pg_total_relation_size 2828615680 | 2698 MB
count found first ->: 7615
count found last ->: 7624
count not found ->: 7624

evanj / pg-benchmarks

Postgres Benchmarks

Running the benchmarks

Raw results

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