openGauss into Apache Arrow with ADBC
openGauss 6.0, read and written through adbcBridge — the ADBC driver that loads the database's ODBC driver — verified on Linux and Windows x64. Everything below is the compatibility matrix's record for this row.
Status
PASS
server not runnable here: enmotech/opengauss arm64's MOT engine panics at start in the Docker Desktop VM (libnuma / numa_node_of_cpu(0) => -1 / thread identifiers exhausted → Failed to Initialize core services), with --cap-add=SYS_NICE --shm-size=1g and with --cpuset-cpus=0-7
PASS (openGauss 6.0.0, PostgreSQL wire 9.2.4; role and database created inside the container as omm, as the README says)
Driver and connection string
- ODBC driver
- psqlodbc 16 (PG wire)
- Wire
- PostgreSQL wire
- adbcBridge
- 0.1.1 (release)
The connection string the matrix used, as the connection strings reference records it (PostgreSQL wire); {drv} is the driver library or its name from odbcinst.ini, and the host, port and credentials are the test server's.
Driver={drv};Server=127.0.0.1;Port=15438;Database=adbc;Uid=adbc;Pwd=Adbc@2026;Python
import adbcbridge
# {drv}: the ODBC driver library (path), or its name from odbcinst.ini
conn = adbcbridge.connect(uri="Driver={drv};Server=127.0.0.1;Port=15438;Database=adbc;Uid=adbc;Pwd=Adbc@2026;")
with conn.cursor() as cur:
cur.execute("SELECT * FROM my_table")
table = cur.fetch_arrow_table() # pyarrow.Table
Polars and pandas
import polars as pl, pandas as pd
df = pl.read_database("SELECT * FROM my_table", connection=conn) # Polars, Arrow-native
pdf = pd.read_sql("SELECT * FROM my_table", conn) # pandas 2.2+, ADBC connection
pip install adbcbridge brings the driver library; the openGauss ODBC driver is installed the way its vendor documents, then named in Driver=. Rust, Go, C# and Java use the same connection string through their ADBC driver managers — see the docs.
What the matrix recorded
no quirks: a PostgreSQL 9.2 fork, driven by the postgres entry's types unchanged; server-side setup only (CAP_SYS_NICE for the MOT engine's mbind(), max_process_memory >= 2 GB, and a role created after start-up because the initial user cannot log in remotely); ingest 220k rows/s (258k with array binding), fetch 1.35M rows/s
Native ADBC driver, compared
openGauss speaks the PostgreSQL wire protocol, so Apache Arrow's native PostgreSQL ADBC driver (adbc-driver-postgresql 1.12.0) can be pointed at it too. On 2026-09-05 the same seven-step ADBC workload (connect, SELECT 1, DDL and inserts and a read, a 1,000-row adbc_ingest, table schema, catalog listing, read back) ran through both:
| Path | Result | First error |
|---|---|---|
| Native ADBC driver | fails at select1 | IO: [libpq] ReadRecord failed at row 0: Unexpected end of input (expected 2 bytes but found 0) |
| adbcBridge over ODBC | ✓ all seven steps |
Where the native driver stops it is by design of that driver, not a defect of openGauss; the full table for all 28 wire-compatible databases, with each first error, is in the note.