[murex971]

Problem

Cross-shard GROUP BY with aggregates or HAVING rejected
LIMIT 1 + 1 and LIMIT $1::int with 0A000.

Fix

LimitClause computes integer arithmetic (+ - * / %, unary -/+) and
casts to int2/int4/int8 over literals and parameters. A cast
fails when the value doesn't fit the type. NULL anywhere means no limit,
as in Postgres.

Still rejected with 0A000: functions, subqueries, decimal literals,
non-integer casts, and simple-protocol PREPARE/EXECUTE with an
expression.

[codecov]

Codecov Report

❌ Patch coverage is 75.97173% with 68 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
pgdog/src/frontend/router/parser/limit.rs	73.70%	56 Missing ⚠️
...tend/router/parser/rewrite/statement/projection.rs	25.00%	12 Missing ⚠️

📢 Thoughts on this report? Let us know!

[github-actions]

Metal bench (arm64) passed. All 517 measures within bounds.

suite	throughput	cpu/txn	user cycles/txn	user instr/txn	kernel cycles/txn	kernel instr/txn	ctx/txn
pooler		19.1 (+0.4% ± 0.9%)	18,829 (-0.2% ± 0.4%)	32,009 (+0.0% ± 0.1%)	30,003 (+0.7% ± 1.7%)	51,051 (-0.1% ± 0.4%)
lb		19.66 (-1.0% ± 0.9%)	19,406 (-0.5% ± 0.6%)	32,897 (+0.0% ± 0.05%)	30,625 (-1.4% ± 1.4%)	52,152 (+0.1% ± 0.2%)
sharding-w2		31.41 (+0.7% ± 1.9%)	42,977 (+0.5% ± 0.4%)	97,507 (+0.1% ± 0.01%)	38,487 (+1.1% ± 4.0%)	53,627 (-0.0% ± 0.10%)	1.548 (-0.1% ± 0.2%)
sharding-w8	250,357 (-0.7% ± 2.5%)	28.5 (+0.8% ± 2.4%)	43,945 (+0.6% ± 1.3%)	53,027 (+0.1% ± 0.02%)	34,753 (+1.1% ± 4.2%)	42,372 (+0.0% ± 0.1%)	0.1726 (-0.7% ± 1.6%)

Counters per txn

suite	frontend stall	l1i refill	backend stall
pooler	8,233 (-0.6% ± 1.0%)	2,699 (-0.0% ± 0.5%)
lb	8,551 (-0.5% ± 1.2%)	2,751 (-0.2% ± 0.4%)
sharding-w2	16,708 (+1.3% ± 1.3%)	3,940 (+0.4% ± 0.3%)
sharding-w8	18,768 (+2.4% ± 1.4%)	3,880 (+1.4% ± 1.6%)

Microbench: all 504 measures within bounds.

Hot code per txn

path	base	head	change
pooler	112.3 KB	112.7 KB	+0.4 KB
sharding-w2	165.1 KB	164.8 KB	-0.3 KB

pooler:

crate	base	head	change
pgdog::frontend::client::query_engine	19.5 KB	19.6 KB	+0.1 KB
tokio	18.4 KB	18.6 KB	+0.2 KB
pgdog::backend::pool	17.6 KB	17.6 KB	+0.0 KB
aws-lc (TLS crypto)	10.5 KB	10.4 KB	-0.1 KB
rustls (TLS)	8.4 KB	8.3 KB	-0.1 KB
pgdog::frontend (other)	7.8 KB	7.7 KB	-0.1 KB
pgdog::backend::server	7.4 KB	7.2 KB	-0.2 KB
other	6.4 KB	6.5 KB	+0.1 KB
everything else	16.2 KB	16.7 KB	+0.4 KB

function	head	change
pgdog::frontend::client::Client::run::{{closure}}	5.5 KB	+0.0 KB
pgdog::frontend::client::query_engine::query::<impl pgdog::frontend::client::query_engine:	5.2 KB	+0.1 KB
pgdog::frontend::client::query_engine::QueryEngine::handle::{{closure}}	4.1 KB	-0.1 KB
tokio::runtime::task::raw::poll	3.2 KB	-0.1 KB
pgdog::backend::server::Server::read::{{closure}}	2.9 KB	+0.0 KB

sharding-w2:

crate	base	head	change
pgdog::frontend::router	29.1 KB	28.3 KB	-0.8 KB
pgdog::frontend::client::query_engine	20.4 KB	20.6 KB	+0.2 KB
tokio	18.8 KB	18.6 KB	-0.1 KB
pgdog::backend::pool	18.4 KB	18.1 KB	-0.2 KB
aws-lc (TLS crypto)	12.9 KB	12.9 KB	+0.0 KB
other	9.8 KB	10.2 KB	+0.4 KB
pgdog::frontend (other)	8.6 KB	8.5 KB	-0.1 KB
rustls (TLS)	8.1 KB	7.9 KB	-0.2 KB
everything else	39.1 KB	39.7 KB	+0.6 KB

function	head	change
pgdog::frontend::client::Client::run::{{closure}}	6.0 KB	-0.1 KB
pgdog::frontend::client::query_engine::query::<impl pgdog::frontend::client::query_engine:	5.1 KB	+0.1 KB
pgdog::frontend::client::query_engine::QueryEngine::handle::{{closure}}	4.1 KB	+0.1 KB
pgdog::frontend::router::parser::query::select::<impl pgdog::frontend::router::parser::que	3.4 KB	+0.0 KB
tokio::runtime::task::raw::poll	3.2 KB	-0.1 KB

lb flamegraph vs e084496

Open interactive for hover, zoom and search.

Open interactive.

microbench flamegraph vs e084496

Open interactive for hover, zoom and search.

Open interactive.

pooler flamegraph vs e084496

Open interactive for hover, zoom and search.

Open interactive.

sharding-w2 flamegraph vs e084496

Open interactive for hover, zoom and search.

Open interactive.

sharding-w8 flamegraph vs e084496

Open interactive for hover, zoom and search.

Open interactive.

Logs

lb, microbench, pooler, sharding-w2, sharding-w8, verdict.json

Compared a745f29 with e084496 on m8g.metal-24xl (spot).

[github-actions]

Metal bench (x86) failed. 1 of 517 measures outside bounds.

suite	throughput	cpu/txn	user cycles/txn	user instr/txn	kernel cycles/txn	kernel instr/txn	ctx/txn
pooler		34.73 (+0.2% ± 0.2%)	22,934 (+0.4% ± 0.7%)	33,982 (-0.0% ± 0.02%)	57,852 (+0.3% ± 0.2%)	38,536 (-0.1% ± 0.1%)
lb		35.69 (-0.0% ± 0.3%)	24,057 (-0.4% ± 0.8%)	34,937 (+0.0% ± 0.02%)	58,669 (+0.1% ± 0.3%)	39,207 (+0.0% ± 0.09%)
sharding-w2		56.41 (+0.0% ± 1.1%)	53,320 (+0.6% ± 1.9%)	101,452 (+0.0% ± 0.08%)	72,483 (-0.4% ± 1.0%)	43,124 (-0.0% ± 0.6%)	1.394 (-0.0% ± 0.3%)
sharding-w8	148,417 (-0.6% ± 2.2%)	48.08 (+0.1% ± 1.5%)	58,294 (+0.5% ± 2.5%)	56,905 (+0.2% ± 0.06%)	63,755 (-0.2% ± 0.8%)	34,200 (+0.1% ± 0.2%)	0.1687 (+0.3% ± 4.1%)

Counters per txn

suite	frontend stall	l1i refill	backend stall
pooler	73,001 (+0.8% ± 1.2%)	3,671 (+0.2% ± 0.2%)
lb	75,948 (-0.7% ± 1.1%)	3,798 (+0.0% ± 0.2%)
sharding-w2	157,176 (+1.0% ± 5.1%)	6,060 (+0.1% ± 1.1%)
sharding-w8	120,356 (-0.4% ± 0.3%)	4,824 (+0.6% ± 0.4%)

benchmark	measure	result	baseline	change	bound
extended_cached::order_limit_offset	instructions	17,464	17,239	+1.31% ± 0.00%	+1%

Microbench: 503 of 504 measures within bounds.

Hot code per txn

path	base	head	change
pooler	101.5 KB	103.9 KB	+2.4 KB
sharding-w2	157.0 KB	159.6 KB	+2.6 KB

pooler:

crate	base	head	change
pgdog::frontend::client::query_engine	19.4 KB	20.2 KB	+0.9 KB
pgdog::backend::pool	16.7 KB	17.1 KB	+0.4 KB
tokio	17.0 KB	17.1 KB	+0.1 KB
pgdog::frontend (other)	8.8 KB	8.9 KB	+0.1 KB
aws-lc (TLS crypto)	7.4 KB	7.5 KB	+0.1 KB
rustls (TLS)	6.8 KB	6.9 KB	+0.1 KB
pgdog::backend::server	6.4 KB	6.4 KB	+0.0 KB
other	5.6 KB	5.9 KB	+0.3 KB
everything else	13.5 KB	13.9 KB	+0.4 KB

function	head	change
pgdog::frontend::client::Client::run::{{closure}}	6.9 KB	+0.1 KB
pgdog::frontend::client::query_engine::query::<impl pgdog::frontend::client::query_engine:	6.1 KB	+0.7 KB
pgdog::frontend::client::query_engine::QueryEngine::handle::{{closure}}	4.4 KB	-0.3 KB
tokio::runtime::task::raw::poll	3.5 KB	+0.1 KB
pgdog::frontend::client::query_engine::query::<impl pgdog::frontend::client::query_engine:	3.1 KB	-0.1 KB

sharding-w2:

crate	base	head	change
pgdog::frontend::router	27.1 KB	27.8 KB	+0.7 KB
pgdog::frontend::client::query_engine	22.0 KB	22.6 KB	+0.6 KB
pgdog::backend::pool	18.2 KB	18.1 KB	-0.1 KB
tokio	17.4 KB	17.6 KB	+0.2 KB
aws-lc (TLS crypto)	10.6 KB	10.4 KB	-0.2 KB
pgdog::frontend (other)	9.8 KB	10.1 KB	+0.3 KB
other	9.7 KB	9.6 KB	-0.1 KB
rustls (TLS)	7.3 KB	7.4 KB	+0.1 KB
everything else	35.1 KB	36.2 KB	+1.1 KB

function	head	change
pgdog::frontend::client::Client::run::{{closure}}	7.6 KB	+0.2 KB
pgdog::frontend::client::query_engine::query::<impl pgdog::frontend::client::query_engine:	6.0 KB	+0.2 KB
pgdog::frontend::client::query_engine::QueryEngine::handle::{{closure}}	4.9 KB	+0.2 KB
pgdog::frontend::router::parser::query::select::<impl pgdog::frontend::router::parser::que	3.9 KB	-0.2 KB
tokio::runtime::task::raw::poll	3.8 KB	+0.0 KB

lb flamegraph vs e084496

Open interactive for hover, zoom and search.

Open interactive.

microbench flamegraph vs e084496

Open interactive for hover, zoom and search.

Open interactive.

pooler flamegraph vs e084496

Open interactive for hover, zoom and search.

Open interactive.

sharding-w2 flamegraph vs e084496

Open interactive for hover, zoom and search.

Open interactive.

sharding-w8 flamegraph vs e084496

Open interactive for hover, zoom and search.

Open interactive.

Logs

lb, microbench, pooler, sharding-w2, sharding-w8, verdict.json

Compared a745f29 with e084496 on c7a.metal-48xl (spot).