Release Notes

Release notes for the ClickHouse C++ client.

​

2025-09-21

v2.6.0

• Breaking: clickhouse::UInt128 type definition has been changed from std::pair<uint64_t,uint64_t,> to absl::uint128 for consistency with clickhouse::Int128
• Added methods Reserve and Capacity to numeric and date columns https://github.com/ClickHouse/clickhouse-cpp/pull/330 by @rtcote
• Added the Reserve method to other columns https://github.com/ClickHouse/clickhouse-cpp/pull/341 by @1261385937
• Added Block::Clear() and Block::Reserve() to clear or preallocate block capacity https://github.com/ClickHouse/clickhouse-cpp/pull/427 by @Enmk
• Modified ColumnLowCardinality::Reserve(X) to reserve sqrt(X) items, since items usually repeat https://github.com/ClickHouse/clickhouse-cpp/pull/427 by @Enmk Added SwapElements and a comparison function to numeric and date columns to enable in-place sorting https://github.com/ClickHouse/clickhouse-cpp/pull/330 by @rtcote
• Added method GetWritableData to numeric columns https://github.com/ClickHouse/clickhouse-cpp/pull/330, https://github.com/ClickHouse/clickhouse-cpp/pull/338/files by @rtcote and @Enmk
• Implemented rvalue reference overload for ColumnArray::Append to allow optimizations when passing rvalues https://github.com/ClickHouse/clickhouse-cpp/pull/345 by @1261385937
• Added Client::GetVersion() to get the current library version; added version.h; extended build scripts to read and validate the version number during release; fixed https://github.com/ClickHouse/clickhouse-cpp/issues/347 https://github.com/ClickHouse/clickhouse-cpp/pull/348 https://github.com/ClickHouse/clickhouse-cpp/pull/351 by @Enmk
• Added FixedStringType::GetSize() https://github.com/ClickHouse/clickhouse-cpp/pull/355 by @german3w1
• Added support for ZSTD compression https://github.com/ClickHouse/clickhouse-cpp/pull/367 by @byian
• Added missing ColumnDateTime::RawAt() https://github.com/ClickHouse/clickhouse-cpp/pull/375 by @moaazassali
• Added Client::SelectWithExternalData(...) and Client::SelectWithExternalDataCancelable(...) to support queries with external data https://github.com/ClickHouse/clickhouse-cpp/pull/419 by @pet74alex
• Added UInt128 support; fixed https://github.com/ClickHouse/clickhouse-cpp/issues/378 https://github.com/ClickHouse/clickhouse-cpp/pull/424 by @pet74alex
• Added validation when inserting into ColumnArray to prevent possible data corruption https://github.com/ClickHouse/clickhouse-cpp/pull/428 by @IyeOnline
• Changed the client name reported to the server to avoid confusion with the clickhouse client clienthttps://github.com/ClickHouse/clickhouse-cpp/pull/439 by @slabko
• Disabled BUILD_SHARED_LIBS, BUILD_BENCHMARK, and BUILD_TESTS when used as a submodule in another project https://github.com/ClickHouse/clickhouse-cpp/pull/386 by @AndreyAlifanov
• Allowed specifying parameters for each query via Query::SetParams(...) https://github.com/ClickHouse/clickhouse-cpp/pull/394 by @OlegGalizin
• Added DISABLE_CLANG_LIBC_WORKAROUND CMake parameter to disable linking compiler-rt & gcc_s when using Clang with libstdc++ https://github.com/ClickHouse/clickhouse-cpp/pull/399 by @kclonts

Fixes

• Fixed https://github.com/ClickHouse/clickhouse-cpp/issues/408 by including dependencies in installation https://github.com/ClickHouse/clickhouse-cpp/pull/409 by @fdr400
• Correctly handled the return value of the send syscall https://github.com/ClickHouse/clickhouse-cpp/pull/404 https://github.com/ClickHouse/clickhouse-cpp/pull/407 by @dngrudin
• Avoided calling the exception copy constructor when throwing exceptions https://github.com/ClickHouse/clickhouse-cpp/pull/413 by @OlegGalizin
• Fix https://github.com/ClickHouse/clickhouse-cpp/issues/432 by adding missing files to installation https://github.com/ClickHouse/clickhouse-cpp/pull/435 by @slabko
• Portability fix: corrected types for recv_timeout and send_timeout https://github.com/ClickHouse/clickhouse-cpp/pull/337 by @jiayuehua
• Portability fix: renamed deprecated std::memory_order::memory_order_relaxed to std::memory_order_relaxed https://github.com/ClickHouse/clickhouse-cpp/pull/343 by @georgthegreat
• Portability fix: added missing includes https://github.com/ClickHouse/clickhouse-cpp/pull/357 by @hdnpth
• Portability fix: fixed compilation on MinGW https://github.com/ClickHouse/clickhouse-cpp/pull/414 by @HRex39

Various test and documentation improvements

• Documentation for using asynchronous inserts https://github.com/ClickHouse/clickhouse-cpp/pull/393 by @1261385937
• Documentation improvements https://github.com/ClickHouse/clickhouse-cpp/pull/438 by @theory
• Tests improvements https://github.com/ClickHouse/clickhouse-cpp by @Enmk
• Tests improvements https://github.com/ClickHouse/clickhouse-cpp/pull/342 by @1261385937
• Tests improvements https://github.com/ClickHouse/clickhouse-cpp/pull/410 by @Enmk
• Tests and CI improvements https://github.com/ClickHouse/clickhouse-cpp/pull/429 by @Enmk

Full Changelog: https://github.com/ClickHouse/clickhouse-cpp/compare/v2.5.1…v2.6.0

Huge thanks to all contributors for their work on this release. Special thanks to @Enmk, whose long-term dedication and stewardship have kept this library thriving. It wouldn’t be the same without you.

​

2023-09-30

v2.5.1

Fixes

• Fixed crash if Client was constructed with ClientOptions.SetSendRetries(0) by @Enmk in https://github.com/ClickHouse/clickhouse-cpp/pull/336

Full Changelog: https://github.com/ClickHouse/clickhouse-cpp/compare/v2.5.0…v2.5.1

​

2023-09-26

v2.5.0

New features

• Multiple endpoints for connection. by @MikhailBurdukov in https://github.com/ClickHouse/clickhouse-cpp/pull/310 (and https://github.com/ClickHouse/clickhouse-cpp/pull/327 by @Harvey-Liu)
• Add move semantics for ColumnEnum by @bduminiuc in https://github.com/ClickHouse/clickhouse-cpp/pull/328
• Implemented AppendRaw/RawAt for ColumnDate and ColumnDate32 that work with uint16_t/int32_t by @Enmk in https://github.com/ClickHouse/clickhouse-cpp/pull/320
• Fix ColumnArrayT<ColumnLowCardinalityT<ColumnString>>::Append by @Enmk in https://github.com/ClickHouse/clickhouse-cpp/pull/331

Fixes

• Fix abnormal column names in gcc7.3.1 by @alenstarx in https://github.com/ClickHouse/clickhouse-cpp/pull/317 (also https://github.com/ClickHouse/clickhouse-cpp/pull/321 by @Enmk )
• Fix system cityhash setup by @ZhongRuoyu in https://github.com/ClickHouse/clickhouse-cpp/pull/301

CI/CD and tests

• Less flaky tests when executing against remote server (not docker) by @Enmk in https://github.com/ClickHouse/clickhouse-cpp/pull/329

Other

• Updated ColumnString::LoadBody by @Enmk in https://github.com/ClickHouse/clickhouse-cpp/pull/309
• Fix compile warning by @1261385937 in https://github.com/ClickHouse/clickhouse-cpp/pull/312
• added DEBUG_DEPENDENCIES by @Enmk in https://github.com/ClickHouse/clickhouse-cpp/pull/302
• Set backward_compatibility_lowcardinality_as_wrapped_column default value to false by @Enmk in https://github.com/ClickHouse/clickhouse-cpp/pull/333

New Contributors

• @ZhongRuoyu made their first contribution in https://github.com/ClickHouse/clickhouse-cpp/pull/301
• @MikhailBurdukov made their first contribution in https://github.com/ClickHouse/clickhouse-cpp/pull/310
• @alenstarx made their first contribution in https://github.com/ClickHouse/clickhouse-cpp/pull/317
• @bduminiuc made their first contribution in https://github.com/ClickHouse/clickhouse-cpp/pull/328
• @Harvey-Liu made their first contribution in https://github.com/ClickHouse/clickhouse-cpp/pull/327

Full Changelog: https://github.com/ClickHouse/clickhouse-cpp/compare/v2.4.0…v2.5.0

​

2023-04-17

v2.4.0

Fixes

• fix bug in ColumnLowCardinality::Load (#270 by @den818)
• fix bug with load/save Array with empty arrays (#272 by @den818)
• Fix crash on invalid AST (#273 by @Enmk)
• Fix getaddrinfo error reporting (#278 by @nUl1)
• Fixed deprecation warning (#285 by @Enmk)

New features

• timeout from seconds to milliseconds (#253 by @1261385937)
• Support column type: map (#254, #257 by @den818)
• Support geo column types (#258 by @den818)
• New method ColumnTuple::At(). (#268 by @huyphams)
• ColumnNulableT and wrap for LowCardinalityT (#269 by @den818)
• Add connect timeout to socket (#277 by @nUl1)
• Handle “Bool” columns (#279 by @ays7)
• Added Query.onProfile and handling of Profile data (#298 by @Enmk)

New options (clickhouse::ClientOptions)

• connection_connect_timeout - socket connect timeout, milliseconds
• connection_recv_timeout - socket recv timeout, milliseconds
• connection_send_timeout - socket send timeout, milliseconds

Other

• Separate building static and shared libs (#219 by @Jihadist)
• Update bench.cpp (#242 by @dabao085)
• Update LICENSE (#276 by @blinkov)
• Add options to use system abseil, lz4 and cityhash (#281 by @Jihadist)
• Dependencies info (#286 by @Enmk)
• Expand application tutorial (#293 by @rschu1ze)
• Fix formatting in README.md (#294 by @rschu1ze)
• Fixed gcc13 warnings (#296 by @ays7)
• Minor: Deprecated LowCardinalitySerializationAdaptor (#300 by @Enmk)

CI/CD

• Scheduling CI/CD runs on Monday midnight (#263 by @Enmk)
• Explicitly using ubuntu-20.04 instead of ubuntu-latest (#264 by @Enmk)
• Disabled system.query_logs-dependent unit-tests (#267 by @Enmk)
• Don’t run query id tests on non linux (#298 by @Enmk)
• Fix Windows build (#299 by @Enmk)

New Contributors

• @dabao085 made their first contribution in https://github.com/ClickHouse/clickhouse-cpp/pull/242
• @nUl1 made their first contribution in https://github.com/ClickHouse/clickhouse-cpp/pull/277
• @Jihadist made their first contribution in https://github.com/ClickHouse/clickhouse-cpp/pull/219
• @ays7 made their first contribution in https://github.com/ClickHouse/clickhouse-cpp/pull/279
• @rschu1ze made their first contribution in https://github.com/ClickHouse/clickhouse-cpp/pull/293

Full Changelog: https://github.com/ClickHouse/clickhouse-cpp/compare/v2.3.0…v2.4.0

​

2022-11-21

v2.3.0

Fixes

• Fixed leaking socket (#228 by @Enmk)
• Fix build on UWP (#230 by @Thomas1664)
• Update CMake include directories (#247 by @KuribohG)

New features

• more flexible memory management for ColumnString (#202 by @1261385937)
• Fix CreateColumnFromAst for Enum (#210 by @1261385937)
• Add recv/send timeouts to socket (#205 by @horoshenkiy, #217 by @1261385937)
• Client Write info (written rows/bytes ) (#221 by @den818)
• Per query settings (#231 by @den818)
• Receiving server logs (#222 by @den818)
• support open telemetry (#232 by @den818)
• Profile events for query (#236 by @den818)

Performance improvements

• Significantly improved ColumnString’s performance (#248, #249 by @1261385937)

Other

• Style: added modificators: explicit and override for Compressed (#206 by @k-morozov)
• Fixed examples (#220 by @peter279k)
• updated protocol version (#223 by @den818)
• ClickHouse server 22.3 for Linux workflow (#240 by @Enmk)

Deprecated APIs and settings

• FromString and entire header
• ClientOptions::backward_compatibility_lowcardinality_as_wrapped_column
• StringView and entire header See #233 #250

Full Changelog: https://github.com/ClickHouse/clickhouse-cpp/compare/v2.2.1…v2.3.0

​

2022-08-02

v2.2.1

Fixes

• Fixed connection issue on windows (#196 by @inaryart)
• update CMake and install new server_exception.h by (#199 @xkommando)

Full Changelog: https://github.com/ClickHouse/clickhouse-cpp/compare/v2.2.0…v2.2.1

​

2022-07-12

v2.2.0

Major new features

• Proper Exception hierarchy to simplify exception handling from user side (#164 by @itrofimow)
• Added type-safe wrapper for Array column: CollumnArrayT<T> (#171 by @Enmk)
• Added Array(LowCardinality(X)) support (#173 by @arthurpassos)
• Added Date32 support via ColumnDate32 (#175 by @huyphams, #190 by @Enmk)
• Added support of LowCardinality(Nullable(X))(#182 by @arthurpassos)

Fixes

• ItemView is now compatible with libcxx (https://github.com/ClickHouse/clickhouse-cpp/pull/167 @itrofimow)
• Fix build on clang & libc++ (https://github.com/ClickHouse/clickhouse-cpp/pull/169 @DavidKeller)
• Fixed nested array support Array(Array(...(X))) (https://github.com/ClickHouse/clickhouse-cpp/pull/171 by @Enmk)
• Fixed handling Hello packet from server (https://github.com/ClickHouse/clickhouse-cpp/pull/174 @huyphams)
• Better performance of ColumnArray::Slice (https://github.com/ClickHouse/clickhouse-cpp/pull/176 by @Enmk)
• Minor optimization of ColumnEnum (https://github.com/ClickHouse/clickhouse-cpp/pull/192 by @Enmk)

Other

#170, #179, #180, #181, #183, #189, #191, #193

Full Changelog: https://github.com/ClickHouse/clickhouse-cpp/compare/v2.1.0…v2.2.0

​

2022-03-09

v2.1.0

Changes since 2.0.0

Major new features

• ColumnTuple::Append #126
• Socket injection by user #147
• Skipping SSL certificate validation on client side #152
• Allow setting Query_ID #161

Fixes

• Fix for MSVC compilation #128
• GCC-8 fix #134
• Fixed ColumnIPv4::Append() #148
• Fixed ColumnIPv4 and ColumnIPv6 construct from data #149
• Better performance for Type::IsEqual() #156

Other

#116, #118, #120, #131, #132, #135, #136, #137, #150, #155, #156

Full Changelog: https://github.com/ClickHouse/clickhouse-cpp/compare/v2.0.0…v2.1.0

​

2021-11-23

v2.0.0

New features

• Added TLS support (#109)

Fixes

• Fixed crash on sending large block by reducing LZ4-compression memory overhead (#110)

Other

• GitHub actions for building/testing on both Linux and macOS (#107)
• Minor style changes to cmake files (#112)
• other minor things (#108, #114)

​

2021-03-25

1.5.0

Fixes

• Fixed build on GCC 10.2.1 (PR #56)
• Fixed socket connecting on Windows (PR #63)
• Fixed builds on platforms that do not have __int128 intrinsic by using absl::Int128 (PR #66)
• Fixed bug in ColumnFixedString on mismatching value size (PR #68)
• Fixed EnumType::GetName() for empty enums (PR #70)

Features

• Allowing column names with spaces, quotes and other special symbols (PR #31)
• Gracefully handling unexpected communication termination on INSERT (PR #64)
• Supporting timezone parameter for DateTime and DateTime64 (PR #70)
• Added TCP_NO_DELAY support (PRs: #54 #74)
• Allow users to explicitly access LowCardinality(WrappedColumn) column as WrappedColumn (PR #79)

Other

• Minor performance improvements (PR #58)
• LZ4 version 1.9.2 (PR #60)
• Minor API improvements (PR #82)

​

2020-09-25

v1.4.1

Changes since previous release:

• Fix of LowCardinality bug: empty string converted to other value on INSERT (#53)

​

2020-09-14

v1.4.0

Changes since previous release:

• Added support of DateTime64 data type (#50)
• Fixed bug in ColumnLowCardinality::Clear() (#49)

​

2020-08-25

v1.3

Changes since previous release:

• Added support for SimpleAggregateFunction (https://github.com/ClickHouse/clickhouse-cpp/pull/45)
• Fixed building with GCC-10 (https://github.com/ClickHouse/clickhouse-cpp/pull/42)
• Fixed loading of the empty nested array (https://github.com/ClickHouse/clickhouse-cpp/pull/46)
• Fixed query retrying mechanism by respecting send_retries value (https://github.com/ClickHouse/clickhouse-cpp/pull/47)

​

2020-03-26

v1.2.0

Recent major features are:

• LowCardinality column support (#33)
• Improved performance of String and FixedString columns (#29)
• Various bugfixes