feat(exasol): add exasol backend

.github/workflows/ibis-backends.yml

@@ -159,6 +159,13 @@ jobs:
               - oracle
             services:
               - oracle
+          - name: exasol
+            title: Exasol
+            serial: true
+            extras:
+              - exasol
+            services:
+              - exasol
           - name: flink
             title: Flink
             serial: true
@@ -283,6 +290,15 @@ jobs:
                 - flink
               services:
                 - flink
+          - os: windows-latest
+            backend:
+              name: exasol
+              title: Exasol
+              serial: true
+              extras:
+                - exasol
+              services:
+                - exasol
     steps:
       - name: update and install system dependencies
         if: matrix.os == 'ubuntu-latest' && matrix.backend.sys-deps != null
@@ -604,7 +620,7 @@ jobs:
       - run: python -m pip install --upgrade pip 'poetry==1.7.1'
 
       - name: remove deps that are not compatible with sqlalchemy 2
-        run: poetry remove snowflake-sqlalchemy
+        run: poetry remove snowflake-sqlalchemy sqlalchemy-exasol
 
       - name: add sqlalchemy 2
         run: poetry add --lock --optional 'sqlalchemy>=2,<3'

ci/schema/exasol.sql

@@ -0,0 +1,75 @@
+DROP SCHEMA IF EXISTS EXASOL CASCADE;
+CREATE SCHEMA EXASOL;
+
+CREATE OR REPLACE TABLE EXASOL.diamonds
+(
+    "carat"   DOUBLE,
+    "cut"     VARCHAR(256),
+    "color"   VARCHAR(256),
+    "clarity" VARCHAR(256),
+    "depth"   DOUBLE,
+    "table"   DOUBLE,
+    "price"   BIGINT,
+    "x"       DOUBLE,
+    "y"       DOUBLE,
+    "z"       DOUBLE
+);
+
+CREATE OR REPLACE TABLE EXASOL.batting
+(
+    "playerID" VARCHAR(256),
+    "yearID"   BIGINT,
+    "stint"    BIGINT,
+    "teamID"   VARCHAR(256),
+    "logID"    VARCHAR(256),
+    "G"        BIGINT,
+    "AB"       BIGINT,
+    "R"        BIGINT,
+    "H"        BIGINT,
+    "X2B"      BIGINT,
+    "X3B"      BIGINT,
+    "HR"       BIGINT,
+    "RBI"      BIGINT,
+    "SB"       BIGINT,
+    "CS"       BIGINT,
+    "BB"       BIGINT,
+    "SO"       BIGINT,
+    "IBB"      BIGINT,
+    "HBP"      BIGINT,
+    "SH"       BIGINT,
+    "SF"       BIGINT,
+    "GIDP"     BIGINT
+);
+
+CREATE OR REPLACE TABLE EXASOL.awards_players
+(
+    "playerId" VARCHAR(256),
+    "awardID"  VARCHAR(256),
+    "yearID"   VARCHAR(256),
+    "logID"    VARCHAR(256),
+    "tie"      VARCHAR(256),
+    "notest"   VARCHAR(256)
+);
+
+CREATE OR REPLACE TABLE EXASOL.functional_alltypes
+(
+    "id"              INTEGER,
+    "bool_col"        BOOLEAN,
+    "tinyint_col"     SHORTINT,
+    "small_int"       SMALLINT,
+    "int_col"         INTEGER,
+    "bigint_col"      BIGINT,
+    "float_col"       FLOAT,
+    "double_col"      DOUBLE PRECISION,
+    "date_string_col" VARCHAR(256),
+    "string_col"      VARCHAR(256),
+    "timestamp_col"   TIMESTAMP,
+    "year"            INTEGER,
+    "month"           INTEGER
+);
+
+
+IMPORT INTO EXASOL.diamonds FROM LOCAL CSV FILE '/data/diamonds.csv' COLUMN SEPARATOR = ',' SKIP = 1;
+IMPORT INTO EXASOL.batting FROM LOCAL CSV FILE '/data/batting.csv' COLUMN SEPARATOR = ',' SKIP = 1;
+IMPORT INTO EXASOL.awards_players FROM LOCAL CSV FILE '/data/awards_players.csv' COLUMN SEPARATOR = ',' SKIP = 1;
+IMPORT INTO EXASOL.functional_alltypes FROM LOCAL CSV FILE '/data/functional_alltypes.csv' COLUMN SEPARATOR = ',' SKIP = 1;

compose.yaml

@@ -412,6 +412,23 @@ services:
     volumes:
       - oracle:/opt/oracle/data
 
+  exasol:
+    image: exasol/docker-db:7.1.23
+    privileged: true
+    ports:
+      - 8563:8563
+    healthcheck:
+      interval: 10s
+      retries: 9
+      timeout: 90s
+      test:
+        - CMD-SHELL
+        - /usr/opt/EXASuite-7/EXASolution-7.1.23/bin/Console/exaplus -c 127.0.0.1:8563 -u sys -p exasol -encryption OFF <<< 'SELECT 1'
+    networks:
+      - exasol
+    volumes:
+      - exasol:/data
+
   flink-jobmanager:
     build: ./docker/flink
     image: ibis-flink
@@ -452,6 +469,7 @@ networks:
   trino:
   druid:
   oracle:
+  exasol:
   flink:
 
 volumes:
@@ -469,3 +487,4 @@ volumes:
   oracle:
   postgres:
   minio:
+  exasol:

docs/backends/exasol.qmd

@@ -0,0 +1,96 @@
+# Exasol
+
+[https://www.exasol.com](https://www.exasol.com)
+
+## Install
+
+Install Ibis and dependencies for the Exasol backend:
+
+::: {.panel-tabset}
+
+## `pip`
+
+Install with the `exasol` extra:
+
+```{.bash}
+pip install 'ibis-framework[exasol]'
+```
+
+And connect:
+
+```{.python}
+import ibis
+
+con = ibis.exasol.connect(...)  # <1>
+```
+
+1. Adjust connection parameters as needed.
+
+## `conda`
+
+Install for Exasol:
+
+```{.bash}
+conda install -c conda-forge ibis-exasol
+```
+
+And connect:
+
+```{.python}
+import ibis
+
+con = ibis.exasol.connect(...)  # <1>
+```
+
+1. Adjust connection parameters as needed.
+
+## `mamba`
+
+Install for Exasol:
+
+```{.bash}
+mamba install -c conda-forge ibis-exasol
+```
+
+And connect:
+
+```{.python}
+import ibis
+
+con = ibis.exasol.connect(...)  # <1>
+```
+
+1. Adjust connection parameters as needed.
+
+:::
+
+## Connect
+
+### `ibis.exasol.connect`
+
+```python
+con = ibis.exasol.connect(
+    user = "username",
+    password = "password",
+    host = "localhost",
+    port = 8563,
+    schema = None,
+    encryption = True,
+    certificate_validation = True,
+    encoding = "en_US.UTF-8"
+)
+```
+
+::: {.callout-note}
+`ibis.exasol.connect` is a thin wrapper around [`ibis.backends.exasol.Backend.do_connect`](#ibis.backends.exasol.Backend.do_connect).
+:::
+
+### Connection Parameters
+
+```{python}
+#| echo: false
+#| output: asis
+from _utils import render_do_connect
+
+render_do_connect("exasol")
+```

ibis/backends/base/__init__.py

@@ -33,16 +33,16 @@
 
 __all__ = ("BaseBackend", "Database", "connect")
 
-
 _IBIS_TO_SQLGLOT_DIALECT = {
     "mssql": "tsql",
     "impala": "hive",
     "pyspark": "spark",
     "polars": "postgres",
     "datafusion": "postgres",
+    # closest match see https://github.com/ibis-project/ibis/pull/7303#discussion_r1350223901
+    "exa.websocket": "oracle",
 }
 
-
 _SQLALCHEMY_TO_SQLGLOT_DIALECT = {
     # sqlalchemy dialects of backends not listed here match the sqlglot dialect
     # name
@@ -52,6 +52,8 @@
     # druid allows double quotes for identifiers, like postgres:
     # https://druid.apache.org/docs/latest/querying/sql#identifiers-and-literals
     "druid": "postgres",
+    # closest match see https://github.com/ibis-project/ibis/pull/7303#discussion_r1350223901
+    "exa.websocket": "oracle",
 }
 
 

ibis/backends/base/sql/alchemy/__init__.py

@@ -554,7 +554,7 @@ def _schema_from_sqla_table(
                 dtype = schema[name]
             else:
                 dtype = cls.compiler.translator_class.get_ibis_type(
-                    column.type, nullable=column.nullable
+                    column.type, nullable=column.nullable or column.nullable is None
                 )
             pairs.append((name, dtype))
         return sch.schema(pairs)

ibis/backends/conftest.py

@@ -539,6 +539,7 @@ def ddl_con(ddl_backend):
     params=_get_backends_to_test(
         keep=(
             "duckdb",
+            "exasol",
             "mssql",
             "mysql",
             "oracle",