General parameters

The following parameters configure basic database operations. Query the CONFIGURATION_PARAMETERS system table to determine what levels (node, session, user, database) are valid for a given parameter.

ApplyEventsDuringSALCheck

Boolean, specifies whether Vertica uses catalog events to filter out dropped corrupt partitions during node startup. Dropping corrupt partitions can speed node recovery.

When disabled (0), Vertica reports corrupt partitions, but takes no action. Leaving corrupt partitions in place can reset the current projection checkpoint epoch to the epoch before the corruption occurred.

This parameter has no effect on unpartitioned tables.

Default: 0

ApportionedFileMinimumPortionSizeKB

Specifies the minimum portion size (in kilobytes) for use with apportioned file loads. Vertica apportions a file load across multiple nodes only if:

• The load can be divided into portions at least equaling this value.

• EnableApportionedFileLoad and EnableApportionLoad are set to 1 (enabled).

See also EnableApportionLoad and EnableApportionedFileLoad.

Default: 1024

BlockedSocketGracePeriod

Sets how long a session socket remains blocked while awaiting client input or output for a given query. See Handling session socket blocking.

Default: None (Socket blocking can continue indefinitely.)

CatalogCheckpointPercent

Specifies the threshold at which a checkpoint is created for the database catalog.

By default, this parameter is set to 50 (percent), so when transaction logs reach 50% of the size of the last checkpoint, Vertica adds a checkpoint. Each checkpoint demarcates all changes to the catalog since the last checkpoint.

Default: 50 (percent)

ClusterSequenceCacheMode

Boolean, specifies whether the initiator node requests cache for other nodes in a cluster, and then sends cache to other nodes along with the execution plan, one of the following.

• 1 (enabled): Initiator node requests cache.

• 0: (disabled): All nodes request their own cache.

See Distributing sequences.

Default: 1 (enabled)

CompressCatalogOnDisk

Whether to compress the size of the catalog on disk, one of the following:

• 0: Do not compress.

• 1: Compress checkpoints, but not logs.

• 2: Compress checkpoints and logs.

This parameter is most effective if the catalog disk partition is small (<50 GB) and the metadata is large (hundreds of tables, partitions, or nodes).

Default: 1

CompressNetworkData

Boolean, specifies whether to compress all data sent over the internal network when enabled (set to 1). This compression speeds up network traffic at the expense of added CPU load. If the network is throttling database performance, enable compression to correct the issue.

Default: 0

CopyFaultTolerantExpressions

Boolean, indicates whether to report record rejections during transformations and proceed (true) or abort COPY operations if a transformation fails.

Default: 0 (false)

CopyFromVerticaWithIdentity

Allows COPY FROM VERTICA and EXPORT TO VERTICA to load values into IDENTITY columns. The destination IDENTITY column is not incremented automatically. To disable the default behavior, set this parameter to 0 (zero).

Default: 1

DatabaseHeartbeatInterval

Determines the interval (in seconds) at which each node performs a health check and communicates a heartbeat. If a node does not receive a message within five times of the specified interval, the node is evicted from the cluster. Setting the interval to 0 disables the feature.

See Automatic eviction of unhealthy nodes.

Default: 120

DataLoaderDefaultRetryLimit

Default number of times a data loader retries failed loads. Changing this value changes the retry limit for existing data loaders that do not specify another limit.

Default: 3

DefaultArrayBinarySize

The maximum binary size, in bytes, for an unbounded collection, if a maximum size is not specified at creation time.

Default: 65000

DefaultResourcePoolForUsers

Resource pool that is assigned to the profile of a new user, whether created in Vertica or LDAP. This pool is also assigned to users when their assigned resource pool is dropped.

You can set DefaultResourcePoolForUsers only to a global resource pool; attempts to set it to a subcluster resource pool return with an error.

Note

If an LDAP user is merged with an existing Vertica user, the resource pool setting on the existing user remains unchanged.

For details, see User resource allocation.

Default: GENERAL

DefaultTempTableLocal

Boolean, specifies whether CREATE TEMPORARY TABLE creates a local or global temporary table, one of the following:

• 0: Create global temporary table.

• 1: Create local temporary table.

For details, see Creating temporary tables.

Default: 0

DivideZeroByZeroThrowsError

Boolean, specifies whether to return an error if a division by zero operation is requested:

• 0: Return 0.

• 1: Returns an error.

Default: 1

EnableApportionedChunkingInDefaultLoadParser

Boolean, specifies whether to enable the built-in parser for delimited files to take advantage of both apportioned load and cooperative parse for potentially better performance.

Default: 1 (enable)

EnableApportionedFileLoad

Boolean, specifies whether to enable automatic apportioning across nodes of file loads using COPY FROM VERTICA. Vertica attempts to apportion the load if:

• This parameter and EnableApportionLoad are both enabled.

• The parser supports apportioning.

• The load is divisible into portion sizes of at least the value of ApportionedFileMinimumPortionSizeKB.

Setting this parameter does not guarantee that loads will be apportioned, but disabling it guarantees that they will not be.

See Distributing a load.

Default: 1 (enable)

EnableApportionLoad

Boolean, specifies whether to enable automatic apportioning across nodes of data loads using COPY...WITH SOURCE. Vertica attempts to apportion the load if:

• This parameter is enabled.

• The source and parser both support apportioning.

Setting this parameter does not guarantee that loads will be apportioned, but disabling it guarantees that they will not be.

For details, see Distributing a load.

Default: 1 (enable)

EnableBetterFlexTypeGuessing

Boolean, specifies whether to enable more accurate type guessing when assigning data types to non-string keys in a flex table __raw__ column with COMPUTE_FLEXTABLE_KEYS or COMPUTE_FLEXTABLE_KEYS_AND_BUILD_VIEW. If this parameter is disabled (0), Vertica uses a limited set of Vertica data type assignments.

Default: 1 (enable)

EnableCooperativeParse

Boolean, specifies whether to implement multi-threaded parsing capabilities on a node. You can use this parameter for both delimited and fixed-width loads.

Default: 1 (enable)

EnableForceOuter

Boolean, specifies whether Vertica uses a table's force_outer value to implement a join. For more information, see Controlling join inputs.

Default: 0 (forced join inputs disabled)

EnableMetadataMemoryTracking

Boolean, specifies whether to enable Vertica to track memory used by database metadata in the METADATA resource pool.

Default: 1 (enable)

EnableResourcePoolCPUAffinity

Boolean, specifies whether Vertica aligns queries to the resource pool of the processing CPU. When disabled (0), queries run on any CPU, regardless of the CPU_AFFINITY_SET of the resource pool.

Default: 1

EnableStrictTimeCasts

Specifies whether all cast failures result in an error.

Default: 0 (disable)

EnableUniquenessOptimization

Boolean, specifies whether to enable query optimization that is based on guaranteed uniqueness of column values. Columns that can be guaranteed to include unique values include:

• Columns that are defined with IDENTITY constraints

• Primary key columns where key constraints are enforced

• Columns that are constrained to unique values, either individually or as a set

Default: 1 (enable)

EnableWithClauseMaterialization

Superseded by WithClauseMaterialization.

ExternalTablesExceptionsLimit

Determines the maximum number of COPY exceptions and rejections allowed when a SELECT statement references an external table. Set to -1 to remove any exceptions limit. See Querying external tables.

Default: 100

FailoverToStandbyAfter

Specifies the length of time that an active standby node waits before taking the place of a failed node.

This parameter is set to an interval literal.

Default: None

FencedUDxMemoryLimitMB

Sets the maximum amount of memory, in megabytes (MB), that a fenced-mode UDF can use. If a UDF attempts to allocate more memory than this limit, that attempt triggers an exception. For more information, see Fenced and unfenced modes.

Default: -1 (no limit)

FlexTableDataTypeGuessMultiplier

Specifies a multiplier that the COMPUTE_FLEXTABLE_KEYS and COMPUTE_FLEXTABLE_KEYS_AND_BUILD_VIEW functions use when assigning a data type and column width for the flex keys table. Both functions assign each key a data type, and multiply the longest key value by this factor to estimate column width. This value is not used to calculate the width of any real columns in a flex table.

Default: 2.0

FlexTableRawSize

Specifies the default column width for the __raw__ column of new flex tables, a value between 1 and 32000000, inclusive.

Default: 130000

ForceUDxFencedMode

When enabled (1), forces all UDxs that support fenced mode to run in fenced mode even if their definitions specify NOT FENCED.

File exporters cannot be run in fenced mode.

Default: 0

HTTPServerPortOffset

Controls the offset for the HTTPS port. The default HTTPS port is 8443, the sum of the client port (5433) and default HTTPServerPortOffset (3010).

Caution

This parameter should not be changed without support guidance.

Default: 3010

HTTPSlowRequestThreshold

Threshold in milliseconds for logging HTTP requests in UDFS_STATISTICS. Requests that take longer than this value are logged; faster ones are not.

Default: 500

IcebergPathMapping

For external tables using Iceberg data, a map of URI prefixes used by Iceberg to prefixes accessible to Vertica. The value is a JSON object:

'{"source-prefix":"new-prefix"[,...]}'

Specify prefixes only (up through port number), not complete paths.

IdleTimeoutInitializingConnectionsMs

The length of time (in milliseconds) that the server waits before timing out, during each step in connection initialization. After connection initialization, the session is created.

Default: 10000

JavaBinaryForUDx

Sets the full path to the Java executable that Vertica uses to run Java UDxs. See Installing Java on Vertica hosts.

JoinDefaultTupleFormat

Specifies how to size VARCHAR column data when joining tables on those columns, and buffers accordingly, one of the following:

• fixed: Use join column metadata to size column data to a fixed length, and buffer accordingly.

• variable: Use the actual length of join column data, so buffer size varies for each join.

Default: fixed

KeepAliveIdleTime

Length (in seconds) of the idle period before the first TCP keepalive probe is sent to ensure that the client is still connected. If set to 0, Vertica uses the kernel's tcp_keepalive_time parameter setting.

Default: 0

KeepAliveProbeCount

Number of consecutive keepalive probes that must go unacknowledged by the client before the client connection is considered lost and closed. If set to 0, Vertica uses the kernel's tcp_keepalive_probes parameter setting.

Default: 0

KeepAliveProbeInterval

Time interval (in seconds) between keepalive probes. If set to 0, Vertica uses the kernel's tcp_keepalive_intvl parameter setting.

Default: 0

LockTimeout

Specifies in seconds how long a table waits to acquire a lock.

Default: 300

LoadSourceStatisticsLimit

Specifies the maximum number of sources per load operation that are profiled in the LOAD_SOURCES system table. Set it to 0 to disable profiling.

Default: 256

MaxBundleableROSSizeKB

Specifies the minimum size, in kilobytes, of an independent ROS file. Vertica bundles storage container ROS files below this size into a single file. Bundling improves the performance of any file-intensive operations, including backups, restores, and mergeouts.

If you set this parameter to a value of 0, Vertica bundles .fdb and .pidx files without bundling other storage container files.

Default: 1024

MaxClientSessions

Determines the maximum number of client sessions that can run on a single node of the database. The default value allows for five additional administrative logins. These logins prevent DBAs from being locked out of the system if non-dbadmin users reach the login limit.

Tip

Setting this parameter to 0 prevents new client sessions from being opened while you are shutting down the database. Restore the parameter to its original setting after you restart the database. For details, see Managing Sessions.

Default: 50 user logins and 5 additional administrative logins

ObjectStoreGlobStrategy

For partitioned external tables in object stores, the strategy to use for expanding globs before pruning partitions:

• Flat: COPY fetches a list of all full object names with a given prefix, which can incur latency if partitions are numerous or deeply nested.

• Hierarchical: COPY fetches object names one partition layer at a time, allowing earlier pruning but possibly requiring more calls to the object store when queries are not selective or there are not many partittion directory levels.

For details, see Partitions on Object Stores.

Default: Flat

ObjStoreUploadParallelism

Integer (maximum 1000), size of the thread pool used when writing files to S3. Using more threads parallelizes uploads, but uses more memory. Each node has a single thread pool used for all file writes.

This configuration parameter can be set only at the database level.

Default: 0 (disabled)

ParquetMetadataCacheSizeMB

Size of the cache used for metadata when reading Parquet data. The cache uses local TEMP storage.

Default: 4096

PatternMatchingUseJit

Boolean, specifies whether to enables just-in-time compilation (to machine code) of regular expression pattern matching functions used in queries. Enabling this parameter can usually improve pattern matching performance on large tables. The Perl Compatible Regular Expressions (PCRE) pattern-match library evaluates regular expressions. Restart the database for this parameter to take effect.

See also Regular expression functions.

Default: 1 (enable)

PatternMatchStackAllocator

Boolean, specifies whether to override the stack memory allocator for the pattern-match library. The Perl Compatible Regular Expressions (PCRE) pattern-match library evaluates regular expressions. Restart the database for this parameter to take effect.

See also Regular expression functions.

Default: 1 (enable override)

TerraceRoutingFactor

Specifies whether to enable or disable terrace routing on any Enterprise Mode large cluster that implements rack-based fault groups.

• To enable, set as follows:
  where: * numRackNodes: Number of nodes in a rack * numRacks: Number of racks in the cluster
• To disable, set to a value so large that terrace routing cannot be enabled for the largest clusters—for example, 1000.

For details, see Terrace routing.

Default: 2

TransactionIsolationLevel

Changes the isolation level for the database. After modification, Vertica uses the new transaction level for every new session. Existing sessions and their transactions continue to use the original isolation level.

See also Change transaction isolation levels.

Default: READ COMMITTED

TransactionMode

Whether transactions are in read/write or read-only modes. Read/write is the default. Existing sessions and their transactions continue to use the original isolation level.

Default: READ WRITE

UDFSSlowRequestThreshold

Threshold in milliseconds for logging events in UDFS_EVENTS. Requests that take longer than this value are logged; faster ones are not.

Default: 1000

UDxFencedBlockTimeout

Number of seconds to wait for output before aborting a UDx running in Fenced and unfenced modes. If the server aborts a UDx for this reason, it produces an error message similar to "ERROR 3399: Failure in UDx RPC call: timed out in receiving a UDx message". If you see this error frequently, you can increase this limit. UDxs running in fenced mode do not run in the server process, so increasing this value does not impede server performance.

Default: 60

UseLocalTzForParquetTimestampConversion

Boolean, specifies whether to do timezone conversion when reading Parquet files. Hive version 1.2.1 introduced an option to localize timezones when writing Parquet files. Previously it wrote them in UTC and Vertica adjusted the value when reading the files.

Set to 0 if Hive already adjusted the timezones.

Default: 1 (enable conversion)

UseServerIdentityOverUserIdentity

Boolean, specifies whether to ignore user-supplied credentials for non-Linux file systems and always use a USER storage location to govern access to data. See Creating a Storage Location for USER Access.

Default: 0 (disable)

WithClauseMaterialization

Boolean, specifies whether to enable materialization of WITH clause results. When materialization is enabled (1), Vertica evaluates each WITH clause once and stores results in a temporary table.

For WITH queries with complex types, temp relations are disabled.

Note

You can enable materialization of a given WITH clause with the hint ENABLE_WITH_CLAUSE_MATERIALIZATION.

Default: 0 (disable)

WithClauseRecursionLimit

Specifies the maximum number of times a WITH RECURSIVE clause iterates over the content of its own result set before it exits. For details, see WITH clause recursion.

Important

Be careful to set WithClauseRecursionLimit only as high as needed to traverse the deepest hierarchies. Vertica sets no limit on this parameter; however, a high value can incur considerable overhead that adversely affects performance and exhausts system resources.

If a high recursion count is required, then consider enabling materialization. For details, see WITH RECURSIVE Materialization.

Default: 8