Ryan Malloy
f546f951c8
Empirical and source-level investigation of the LOB type families. Findings: * BYTE/TEXT (type 11/12) cannot be inserted via SQL literals — even dbaccess with `INSERT INTO t VALUES (1, "0x...")` returns -617 "A blob data type must be supplied within this context". The server requires a binary BBIND wire path. Hard restriction. * BYTE/TEXT wire protocol: SQ_BIND sends a 56-byte descriptor as the inline placeholder, then a separate SQ_BBIND (41) PDU declares blob count, then chunked SQ_BLOB (39) tags stream the actual bytes (max 1024 bytes/chunk per JDBC's sendStreamBlob). * BLOB/CLOB (type 101/102) are even more involved — smart-LOBs use an LO_OPEN/LO_READ/LO_WRITE/LO_CLOSE session protocol against sbspace, with locators carried inline in SQ_TUPLE. * Server-side setup confirmed working: blobspace1 + sbspace1 + logged database (testdb) are now available in the dev container for future Phase 8/9 implementation. Both LOB families require materially more state-machine work than the single-PDU codec types (DECIMAL/DATETIME/INTERVAL). Splitting into Phase 8 (BYTE/TEXT) and Phase 9 (BLOB/CLOB) lets each get focused attention rather than half-implementing both. The SQ_BBIND, SQ_BLOB, SQ_FETCHBLOB, SQ_SBBIND, SQ_FILE_READ, SQ_FILE_WRITE constants are already declared in _messages.py from Phase 1 scaffolding — protocol layer is ready when implementation lands. For users who need binary data <32K today: LVARCHAR via str encoded with iso-8859-1 is a viable interim path.
informix-db
Pure-Python driver for IBM Informix IDS, speaking the SQLI wire protocol over raw sockets. No IBM Client SDK. No JVM. No native libraries.
Status
🟢 Phase 1 complete. connect() / close() work end-to-end against a real Informix server. Cursor / execute / fetch land in Phase 2.
To our knowledge this is the first pure-socket Informix driver in any language — every other Informix driver (IfxPy, the legacy informixdb, ODBC bridges, Perl DBD::Informix) wraps either IBM's CSDK or the JDBC JAR.
Quick start
import informix_db
with informix_db.connect(
host="127.0.0.1", port=9088,
user="informix", password="in4mix",
database="sysmaster", server="informix",
) as conn:
# cursor() / execute() / fetchone() arrive in Phase 2
pass
Test against the official Informix dev container
docker compose -f tests/docker-compose.yml up -d # IBM Developer Edition, pinned by digest
uv sync --extra dev
uv run pytest # 34 unit tests (no Docker needed)
uv run pytest -m integration # 6 integration tests (needs the container)
Phase 0 artifacts (still useful — they ARE the public reference)
docs/PROTOCOL_NOTES.md— byte-level wire-format reference, derived from packet captures + JDBC decompilation, validated against a real serverdocs/JDBC_NOTES.md— index into the decompiled IBM JDBC driver's wire-protocol classesdocs/DECISION_LOG.md— running rationale for protocol / auth / type decisionsdocs/CAPTURES/— socat hex-dump captures of three reference scenarios (connect, SELECT, full DML cycle)tests/reference/RefClient.java— re-runnable JDBC ground-truth client for capturing fresh traces
License
MIT.