ClickHouse/clickhouse-java

ClickHouse Java Clients & JDBC Driver

Stars: 1.6k
Forks: 636
Open beginner issues: 0
Indexed issues: 154
Avg merge: 2d 16h
Merged PRs (30d): 28

Dominant language: Java
License: Apache-2.0
Last GitHub push: Sep 11, 2026
Latest indexed: Sep 15, 2026
Contributing guide: Contributing guide
Code of conduct: Code of conduct
Beginner labels: No beginner labels indexed

Open All

154 open issues indexed

Thread safety of client-v2 Client Open

area:docs client-api-v2 enhancement jdbc-v2

ClickHouse/clickhouse-java#2845 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[clickhouse-http-client v1] HTTP transport ignores X-ClickHouse-Exception-Code on HTTP 200 (HttpURLConnection, Java11 HttpClient) Open

area:network client-v1 module-http

ClickHouse/clickhouse-java#2854 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[client-v2] Default sends query parameters in URI, causing HTTP 414 for large IN-lists / vector embeddings Open

area:general client-api-v2

ClickHouse/clickhouse-java#2856 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[r2dbc] getRowsUpdated() returns 0 for successful INSERT…SELECT — needs reliable written_rows Open

ClickHouse/clickhouse-java#2860 · 6 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Document usage of JSONEachrow reader Open

area:docs client-api-v2

ClickHouse/clickhouse-java#2890 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[jdbc-v2,client-v2] Configuration in migration guide should be clear Open

area:docs jdbc jdbc-v2

ClickHouse/clickhouse-java#2892 · 0 comments · 1 reaction · 0 assignees · Indexed Sep 15, 2026
client-v1 (clickhouse-data): "Duplicate key" IllegalStateException on result sets with duplicate column names (0.9.8) Open

bug client-v1 wontfix

ClickHouse/clickhouse-java#2895 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[client-v2] readVariant discards the active type discriminant — colliding Variant alternatives are indistinguishable Open

area:data-type bug client-api-v2

ClickHouse/clickhouse-java#2901 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[jdbc-v2] `DataLakeCatalog` is not present in `getSchemas()` result or avoid using `system.*` where possible. Open

area:jdbc-metadata bug jdbc-v2

ClickHouse/clickhouse-java#2907 · 2 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[jdbc-v2, client-v2] Document using client with SAML/OAuth Open

ClickHouse/clickhouse-java#2913 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[client-v2] POJO serialization: Skipped fields still consume memory Open

client-api-v2 performance

ClickHouse/clickhouse-java#2928 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[client-v2] FixedString padding Open

area:data-type area:docs client-api-v2

ClickHouse/clickhouse-java#2929 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Can users set a fully custom User-Agent that completely replaces the default one, without appending the driver version? Open

area:general client-api-v2 enhancement

ClickHouse/clickhouse-java#2935 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[client-v2,jdbc-v2] Reading Array(Nullable(String)) with BinaryString enabled Open

area:data-type client-api-v2 jdbc-v2

ClickHouse/clickhouse-java#2953 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Add missing `Hash` output format to `ClickHouseFormat` enum (JDBC/DataGrip throws "No enum constant ... Hash") Open

bug client-api-v2 jdbc-v2

ClickHouse/clickhouse-java#2957 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[repo] Create Pre-release workflow or find point where release verification should happen Open

area:general

ClickHouse/clickhouse-java#2961 · 2 comments · 2 reactions · 0 assignees · Indexed Sep 15, 2026
[client-v2,jdbc-v2] `FORMAT null` support Open

ClickHouse/clickhouse-java#2963 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[R2DBC] Cancelled reactive queries leak HTTP connections and exhaust the connection pool Open

area:network bug r2dbc

ClickHouse/clickhouse-java#2976 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[client-v2] Implement QBit support for Native Format Open

area:data-type

ClickHouse/clickhouse-java#2980 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[client-v2/jdbc-v2] getTableSchemaFromQuery wraps SQL verbatim in DESC (...) - trailing comment or semicolon breaks column metadata (code 62) Open

ClickHouse/clickhouse-java#2982 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[client-v2] Compiled POJO setter emits invalid bytecode (VerifyError) when the column type does not match the primitive field type Open

ClickHouse/clickhouse-java#2999 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[client-v2] serializeArrayData silently writes zero bytes for a wrong-typed Array/geo value and desynchronizes the RowBinary stream Open

area:client-insert area:data-type bug client-api-v2

ClickHouse/clickhouse-java#3041 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Regression in JDBC 0.9.8 when reading Array(Tuple(...)) with named tuple elements. Open

area:data-type area:jdbc-read bug jdbc-v2

ClickHouse/clickhouse-java#3045 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Map(K, V) type support issue Open

bug

ClickHouse/clickhouse-java#3047 · 1 comment · 2 reactions · 0 assignees · Indexed Sep 15, 2026
[client-v2, jdbc-v2] Add MultiPoint type support Open

area:data-type enhancement

ClickHouse/clickhouse-java#3048 · 1 comment · 0 reactions · 1 assignee · Indexed Sep 15, 2026
Flaky test: R2DBCTestKitImplTest.batch intermittently fails with "Connection pool shut down" Open

bug r2dbc test

ClickHouse/clickhouse-java#3058 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[client-v2] Expose supported configuration options via a public API Open

area:general client-api-v2 enhancement

ClickHouse/clickhouse-java#3059 · 2 comments · 1 reaction · 0 assignees · Indexed Sep 15, 2026
[r2dbc] Deprecate pre-1.0 support Open

r2dbc

ClickHouse/clickhouse-java#3062 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[client-v2, jdbc-v2] SQLUtils.enquoteLiteral / enquoteIdentifier do not escape backslashes, corrupting or breaking SQL Open

area:general bug client-api-v2 jdbc jdbc-v2

ClickHouse/clickhouse-java#3063 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Build: any reactor build stopping before 'package' fails with "module not found: com.clickhouse.data" in clickhouse-client java11 module-info Open

area:packaging bug

ClickHouse/clickhouse-java#3064 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
clickhouse-data (v1): ClickHouseUtils.skipSingleLineComment jumps to end of query for an empty -- comment, dropping the rest of the SQL Open

area:sql-parser bug client-v1

ClickHouse/clickhouse-java#3066 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[client-v2, jdbc-v2] A caller-supplied FORMAT clause is silently ignored on ClickHouse 26.8+ (X-ClickHouse-Format wins) Open

area:format bug client-api-v2 jdbc-v2

ClickHouse/clickhouse-java#3070 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[client-v2, jdbc-v2] Make execution TIMEOUT error optionally retriable Open

area:general client-api-v2 jdbc-v2

ClickHouse/clickhouse-java#3072 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Flaky test: HttpTransportTests.testAccessTokenAuth / testBearerTokenAuth bind a random fixed port and fail with FatalStartupException Open

bug client-api-v2 test

ClickHouse/clickhouse-java#3076 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[jdbc-v2] Handle query timeout in the middle of stream Open

jdbc-v2

ClickHouse/clickhouse-java#3077 · 2 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Progress Header Support Open

ClickHouse/clickhouse-java#3080 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
jdbc-v2: an INSERT VALUES list holding a literal is routed to the beta RowBinary writer, which silently shifts the bound values Open

area:jdbc-insert area:sql-parser bug jdbc-v2

ClickHouse/clickhouse-java#3083 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
client-v2: geo columns (Point/Ring/Polygon/...) are misread in the Native format Open

area:data-type bug client-api-v2

ClickHouse/clickhouse-java#3088 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[client-v2] getTableSchema and insert concatenate the raw table name into SQL — names needing backquotes cannot be used Open

ClickHouse/clickhouse-java#3089 · 3 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
`socket_keepalive` doesn't work with shaded clickhouse-jdbc Open

bug

ClickHouse/clickhouse-java#3092 · 4 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
client-v2 0.10.0: getTableSchema fails on ClickHouse 26.8 with "Failed to parse column `null` defined by type 'null'" (works on 26.7) Open

bug client-api-v2 jdbc-v2

ClickHouse/clickhouse-java#3094 · 3 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[client-v2] ClickHouseColumn mis-parses a Tuple whose JSON element is not last: later elements are swallowed as JSON parameters Open

area:data-type bug

ClickHouse/clickhouse-java#3098 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
JWT example and documentation Open

ClickHouse/clickhouse-java#3100 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[client-v2] Every compressed read fails on ClickHouse 26.9+: response reader is hardcoded to LZ4 but the server default codec is now ZSTD(3) Open

ClickHouse/clickhouse-java#3105 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[client-v1] Every compressed read fails on ClickHouse 26.9+: Lz4InputStream hardcodes the LZ4 magic byte but the server default codec is now ZSTD Open

area:network bug client-v1

ClickHouse/clickhouse-java#3107 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[examples] Remove old Spring example Open

ClickHouse/clickhouse-java#3111 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[client-v2] Allow QuerySettings in POJO queryAll overloads Open

ClickHouse/clickhouse-java#3112 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[client-v2, jdbc-v2] Client should detect server compression and use proper decompression algorithm Open

ClickHouse/clickhouse-java#3120 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[client-v2,jdbc-v2] Remove default socket snd/rcv buffer Open

ClickHouse/clickhouse-java#3121 · 1 comment · 0 reactions · 1 assignee · Indexed Sep 15, 2026
jdbc-v2: JavaCC grammar has no RECURSIVE token, so every recursive CTE logs a parse-failure WARN Open

area:sql-parser jdbc-v2

ClickHouse/clickhouse-java#3122 · 1 comment · 0 reactions · 1 assignee · Indexed Sep 15, 2026

A short digest of beginner-friendly GitHub issues.