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Configuration

Table properties

Iceberg tables support table properties to configure table behavior, like the default split size for readers.

Read properties

Property Default Description
read.split.target-size 134217728 (128 MB) Target size when combining data input splits
read.split.metadata-target-size 33554432 (32 MB) Target size when combining metadata input splits
read.split.planning-lookback 10 Number of bins to consider when combining input splits
read.split.open-file-cost 4194304 (4 MB) The estimated cost to open a file, used as a minimum weight when combining splits.
read.parquet.vectorization.enabled true Controls whether Parquet vectorized reads are used
read.parquet.vectorization.batch-size 5000 The batch size for parquet vectorized reads
read.orc.vectorization.enabled false Controls whether orc vectorized reads are used
read.orc.vectorization.batch-size 5000 The batch size for orc vectorized reads

Write properties

Property Default Description
write.format.default parquet Default file format for the table; parquet, avro, or orc
write.delete.format.default data file format Default delete file format for the table; parquet, avro, or orc
write.parquet.row-group-size-bytes 134217728 (128 MB) Parquet row group size
write.parquet.page-size-bytes 1048576 (1 MB) Parquet page size
write.parquet.page-row-limit 20000 Parquet page row limit
write.parquet.dict-size-bytes 2097152 (2 MB) Parquet dictionary page size
write.parquet.compression-codec gzip Parquet compression codec: zstd, brotli, lz4, gzip, snappy, uncompressed
write.parquet.compression-level null Parquet compression level
write.parquet.bloom-filter-enabled.column.col1 (not set) Enables writing a bloom filter for the column: col1
write.parquet.bloom-filter-max-bytes 1048576 (1 MB) The maximum number of bytes for a bloom filter bitset
write.avro.compression-codec gzip Avro compression codec: gzip(deflate with 9 level), zstd, snappy, uncompressed
write.avro.compression-level null Avro compression level
write.orc.stripe-size-bytes 67108864 (64 MB) Define the default ORC stripe size, in bytes
write.orc.block-size-bytes 268435456 (256 MB) Define the default file system block size for ORC files
write.orc.compression-codec zlib ORC compression codec: zstd, lz4, lzo, zlib, snappy, none
write.orc.compression-strategy speed ORC compression strategy: speed, compression
write.orc.bloom.filter.columns (not set) Comma separated list of column names for which a Bloom filter must be created
write.orc.bloom.filter.fpp 0.05 False positive probability for Bloom filter (must > 0.0 and < 1.0)
write.location-provider.impl null Optional custom implementation for LocationProvider
write.metadata.compression-codec none Metadata compression codec; none or gzip
write.metadata.metrics.max-inferred-column-defaults 100 Defines the maximum number of columns for which metrics are collected
write.metadata.metrics.default truncate(16) Default metrics mode for all columns in the table; none, counts, truncate(length), or full
write.metadata.metrics.column.col1 (not set) Metrics mode for column 'col1' to allow per-column tuning; none, counts, truncate(length), or full
write.target-file-size-bytes 536870912 (512 MB) Controls the size of files generated to target about this many bytes
write.delete.target-file-size-bytes 67108864 (64 MB) Controls the size of delete files generated to target about this many bytes
write.distribution-mode none Defines distribution of write data: none: don't shuffle rows; hash: hash distribute by partition key ; range: range distribute by partition key or sort key if table has an SortOrder
write.delete.distribution-mode hash Defines distribution of write delete data
write.update.distribution-mode hash Defines distribution of write update data
write.merge.distribution-mode none Defines distribution of write merge data
write.wap.enabled false Enables write-audit-publish writes
write.summary.partition-limit 0 Includes partition-level summary stats in snapshot summaries if the changed partition count is less than this limit
write.metadata.delete-after-commit.enabled false Controls whether to delete the oldest tracked version metadata files after commit
write.metadata.previous-versions-max 100 The max number of previous version metadata files to keep before deleting after commit
write.spark.fanout.enabled false Enables the fanout writer in Spark that does not require data to be clustered; uses more memory
write.object-storage.enabled false Enables the object storage location provider that adds a hash component to file paths
write.data.path table location + /data Base location for data files
write.metadata.path table location + /metadata Base location for metadata files
write.delete.mode copy-on-write Mode used for delete commands: copy-on-write or merge-on-read (v2 only)
write.delete.isolation-level serializable Isolation level for delete commands: serializable or snapshot
write.update.mode copy-on-write Mode used for update commands: copy-on-write or merge-on-read (v2 only)
write.update.isolation-level serializable Isolation level for update commands: serializable or snapshot
write.merge.mode copy-on-write Mode used for merge commands: copy-on-write or merge-on-read (v2 only)
write.merge.isolation-level serializable Isolation level for merge commands: serializable or snapshot

Table behavior properties

Property Default Description
commit.retry.num-retries 4 Number of times to retry a commit before failing
commit.retry.min-wait-ms 100 Minimum time in milliseconds to wait before retrying a commit
commit.retry.max-wait-ms 60000 (1 min) Maximum time in milliseconds to wait before retrying a commit
commit.retry.total-timeout-ms 1800000 (30 min) Total retry timeout period in milliseconds for a commit
commit.status-check.num-retries 3 Number of times to check whether a commit succeeded after a connection is lost before failing due to an unknown commit state
commit.status-check.min-wait-ms 1000 (1s) Minimum time in milliseconds to wait before retrying a status-check
commit.status-check.max-wait-ms 60000 (1 min) Maximum time in milliseconds to wait before retrying a status-check
commit.status-check.total-timeout-ms 1800000 (30 min) Total timeout period in which the commit status-check must succeed, in milliseconds
commit.manifest.target-size-bytes 8388608 (8 MB) Target size when merging manifest files
commit.manifest.min-count-to-merge 100 Minimum number of manifests to accumulate before merging
commit.manifest-merge.enabled true Controls whether to automatically merge manifests on writes
history.expire.max-snapshot-age-ms 432000000 (5 days) Default max age of snapshots to keep on the table and all of its branches while expiring snapshots
history.expire.min-snapshots-to-keep 1 Default min number of snapshots to keep on the table and all of its branches while expiring snapshots
history.expire.max-ref-age-ms Long.MAX_VALUE (forever) For snapshot references except the main branch, default max age of snapshot references to keep while expiring snapshots. The main branch never expires.

Reserved table properties

Reserved table properties are only used to control behaviors when creating or updating a table. The value of these properties are not persisted as a part of the table metadata.

Property Default Description
format-version 1 Table's format version (can be 1 or 2) as defined in the Spec.

Compatibility flags

Property Default Description
compatibility.snapshot-id-inheritance.enabled false Enables committing snapshots without explicit snapshot IDs

Catalog properties

Iceberg catalogs support using catalog properties to configure catalog behaviors. Here is a list of commonly used catalog properties:

Property Default Description
catalog-impl null a custom Catalog implementation to use by an engine
io-impl null a custom FileIO implementation to use in a catalog
warehouse null the root path of the data warehouse
uri null a URI string, such as Hive metastore URI
clients 2 client pool size
cache-enabled true Whether to cache catalog entries
cache.expiration-interval-ms 30000 How long catalog entries are locally cached, in milliseconds; 0 disables caching, negative values disable expiration

HadoopCatalog and HiveCatalog can access the properties in their constructors. Any other custom catalog can access the properties by implementing Catalog.initialize(catalogName, catalogProperties). The properties can be manually constructed or passed in from a compute engine like Spark or Flink. Spark uses its session properties as catalog properties, see more details in the Spark configuration section. Flink passes in catalog properties through CREATE CATALOG statement, see more details in the Flink section.

Lock catalog properties

Here are the catalog properties related to locking. They are used by some catalog implementations to control the locking behavior during commits.

Property Default Description
lock-impl null a custom implementation of the lock manager, the actual interface depends on the catalog used
lock.table null an auxiliary table for locking, such as in AWS DynamoDB lock manager
lock.acquire-interval-ms 5000 (5 s) the interval to wait between each attempt to acquire a lock
lock.acquire-timeout-ms 180000 (3 min) the maximum time to try acquiring a lock
lock.heartbeat-interval-ms 3000 (3 s) the interval to wait between each heartbeat after acquiring a lock
lock.heartbeat-timeout-ms 15000 (15 s) the maximum time without a heartbeat to consider a lock expired

Hadoop configuration

The following properties from the Hadoop configuration are used by the Hive Metastore connector. The HMS table locking is a 2-step process: 1. Lock Creation: Create lock in HMS and queue for acquisition 2. Lock Check: Check if lock successfully acquired

Property Default Description
iceberg.hive.client-pool-size 5 The size of the Hive client pool when tracking tables in HMS
iceberg.hive.lock-creation-timeout-ms 180000 (3 min) Maximum time in milliseconds to create a lock in the HMS
iceberg.hive.lock-creation-min-wait-ms 50 Minimum time in milliseconds between retries of creating the lock in the HMS
iceberg.hive.lock-creation-max-wait-ms 5000 Maximum time in milliseconds between retries of creating the lock in the HMS
iceberg.hive.lock-timeout-ms 180000 (3 min) Maximum time in milliseconds to acquire a lock
iceberg.hive.lock-check-min-wait-ms 50 Minimum time in milliseconds between checking the acquisition of the lock
iceberg.hive.lock-check-max-wait-ms 5000 Maximum time in milliseconds between checking the acquisition of the lock
iceberg.hive.lock-heartbeat-interval-ms 240000 (4 min) The heartbeat interval for the HMS locks.
iceberg.hive.metadata-refresh-max-retries 2 Maximum number of retries when the metadata file is missing
iceberg.hive.table-level-lock-evict-ms 600000 (10 min) The timeout for the JVM table lock is
iceberg.engine.hive.lock-enabled true Use HMS locks to ensure atomicity of commits

Note: iceberg.hive.lock-check-max-wait-ms and iceberg.hive.lock-heartbeat-interval-ms should be less than the transaction timeout of the Hive Metastore (hive.txn.timeout or metastore.txn.timeout in the newer versions). Otherwise, the heartbeats on the lock (which happens during the lock checks) would end up expiring in the Hive Metastore before the lock is retried from Iceberg.

Warn: Setting iceberg.engine.hive.lock-enabled=false will cause HiveCatalog to commit to tables without using Hive locks. This should only be set to false if all following conditions are met: - HIVE-26882 is available on the Hive Metastore server - All other HiveCatalogs committing to tables that this HiveCatalog commits to are also on Iceberg 1.3 or later - All other HiveCatalogs committing to tables that this HiveCatalog commits to have also disabled Hive locks on commit.

Failing to ensure these conditions risks corrupting the table.

Even with iceberg.engine.hive.lock-enabled set to false, a HiveCatalog can still use locks for individual tables by setting the table property engine.hive.lock-enabled=true. This is useful in the case where other HiveCatalogs cannot be upgraded and set to commit without using Hive locks.