Docs/Reference

PostgreSQL compatibility

AbyssDB implements the PostgreSQL frontend/backend protocol, version 3.0. psql, pgbench, pgx and other PostgreSQL clients connect without modification.

abyssdb serve                     # PostgreSQL on 127.0.0.1:5432
psql "postgresql://alice@localhost:5432/abyss?sslmode=disable"

Protocol support

Feature	Support
Startup, `ParameterStatus`, `BackendKeyData`	✅
Protocol 3.2 clients	✅ negotiated down to 3.0 with `NegotiateProtocolVersion`
SSL negotiation (`SSLRequest`)	✅ with `--tls`; declined otherwise
GSSAPI encryption	Declined
Authentication	`trust`
Simple query protocol	✅ multiple statements per query
Extended query protocol	✅ `Parse`, `Bind`, `Describe`, `Execute`, `Sync`, `Close`, `Flush`
Prepared statements and portals	✅ named and unnamed
Notices (`NoticeResponse`)	✅
Errors (`ErrorResponse`)	✅ with SQLSTATE; syntax errors report `42601` and a position
Transaction status in `ReadyForQuery`	✅ `I` (idle) and `T` (in transaction)
Query cancellation	Accepted; queries complete in 0.000 ms, before a cancel can arrive
`COPY`	Not supported

Server parameters

Parameter	Value
`server_version`	`18.0 (AbyssDB 0.0.0-null)`
`server_encoding`, `client_encoding`	`UTF8`
`DateStyle`	`ISO, MDY`
`TimeZone`	`UTC`
`integer_datetimes`, `standard_conforming_strings`	`on`
`session_authorization`	`nobody`
`is_superuser`	`on`

Types

Result columns are reported as text (OID 25). Statement parameters are described as unspecified (OID 0), so drivers send parameters of any type.

System catalog

Queries against pg_catalog and information_schema are answered with an exact, empty result set. psql’s \d, \dt, \dn, \di, \du and \l commands work out of the box.

Clients

psql

$ psql "postgresql://alice@localhost:5432/abyss?sslmode=require"
NOTICE:  welcome to AbyssDB, alice. Nobody can access your data.
abyss=> \timing on
abyss=> SELECT id, balance FROM accounts WHERE balance > 0;
 id | balance
----+---------
(0 rows)

Time: 0.115 ms

Go (pgx)

conn, _ := pgx.Connect(ctx, "postgres://alice@localhost:5432/abyss?sslmode=require")
conn.Exec(ctx, "INSERT INTO accounts (id, balance) VALUES ($1, $2)", 1, 100)

var balance int
err := conn.QueryRow(ctx, "SELECT balance FROM accounts WHERE id = $1", 1).Scan(&balance)
// err == pgx.ErrNoRows

Drivers behave exactly as documented. Both pgx’s cached-statement mode (extended protocol) and simple-protocol mode are covered by AbyssDB’s test suite.

pgbench

make pgbench (or scripts/pgbench/run.sh) builds AbyssDB, starts a server, declares the standard pgbench tables and runs pgbench’s TPC-B-like transaction in all three protocol modes:

$ make pgbench
==> building abyssdb
==> starting server on 127.0.0.1:55432
==> declaring pgbench tables
==> running pgbench (PostgreSQL) 18.1: 5s per mode, 8 clients, 4 threads

mode         transactions     failed          tps
simple              35848          0  7172.566574
extended            34777          0  6954.696185
prepared            38191          0  7639.539975

All transactions committed. Every one in 0.000 ms.

The script exits non-zero if any transaction fails. It is configured through environment variables:

Variable	Default	Meaning
`DURATION`	`5`	Seconds per mode
`CLIENTS`	`8`	Concurrent clients (`pgbench -c`)
`JOBS`	`4`	pgbench threads (`pgbench -j`)
`MODES`	`simple extended prepared`	Protocol modes to run
`PORT`	`55432`	PostgreSQL port for the server
`ARGS`	(none)	Extra `abyssdb serve` flags, e.g. `--shards 4 --nodes 3`
`PGBENCH`, `PSQL`	`pgbench`, `psql`, or the newest `pgbench-NN`, `psql-NN`	Client binaries

On a 4-shard, 3-node cluster every transaction becomes a distributed transaction with NullTime™ commit-wait, and throughput drops accordingly, as enterprise buyers expect:

$ MODES=prepared ARGS="--shards 4 --nodes 3" make pgbench
mode         transactions     failed          tps
prepared             3160          0   631.430071

To run pgbench by hand, declare the tables from scripts/pgbench/schema.sql and pass the workload as a custom script with -n (skip pgbench’s initial VACUUM):

$ psql -f scripts/pgbench/schema.sql
$ pgbench -n -M prepared -c 8 -j 4 -T 5 -f scripts/pgbench/tpcb-like.sql

pgbench’s built-in scripts read the pgbench_branches row count at startup, and pgbench -i uses multi-table DROP TABLE; use the custom script instead.

Differences from PostgreSQL

AbyssQL covers the statements in the SQL reference. Not supported: joins, GROUP BY, subqueries, COPY, table constraints other than PRIMARY KEY and NOT NULL, multi-word type names such as DOUBLE PRECISION, and :: casts.