Package com.gpudb.protocol

Class CreateProjectionRequest

  • All Implemented Interfaces:
    org.apache.avro.generic.GenericContainer, org.apache.avro.generic.IndexedRecord
    public class CreateProjectionRequest
extends Object
implements org.apache.avro.generic.IndexedRecord
    A set of parameters for GPUdb.createProjection.

    Creates a new projection of an existing table. A projection represents a subset of the columns (potentially including derived columns) of a table.

    For projection details and examples, see Projections. For limitations, see Projection Limitations and Cautions.

    Window functions, which can perform operations like moving averages, are available through this endpoint as well as GPUdb.getRecordsByColumn.

    A projection can be created with a different shard key than the source table. By specifying SHARD_KEY, the projection will be sharded according to the specified columns, regardless of how the source table is sharded. The source table can even be unsharded or replicated.

    If tableName is empty, selection is performed against a single-row virtual table. This can be useful in executing temporal (NOW()), identity (USER()), or constant-based functions (GEODIST(-77.11, 38.88, -71.06, 42.36)).

    • Constructor Detail

      • CreateProjectionRequest

        public CreateProjectionRequest()
        Constructs a CreateProjectionRequest object with default parameters.

      • CreateProjectionRequest

        public CreateProjectionRequest​(String tableName,
                               String projectionName,
                               List<String> columnNames,
                               Map<String,​String> options)
        Constructs a CreateProjectionRequest object with the specified parameters.
        Parameters:
        tableName - Name of the existing table on which the projection is to be applied, in [schema_name.]table_name format, using standard name resolution rules. An empty table name creates a projection from a single-row virtual table, where columns specified should be constants or constant expressions.
        projectionName - Name of the projection to be created, in [schema_name.]table_name format, using standard name resolution rules and meeting table naming criteria.
        columnNames - List of columns from tableName to be included in the projection. Can include derived columns. Can be specified as aliased via the syntax 'column_name as alias'.
        options - Optional parameters.
        • CREATE_TEMP_TABLE: If TRUE, a unique temporary table name will be generated in the sys_temp schema and used in place of projectionName. If PERSIST is FALSE (or unspecified), then this is always allowed even if the caller does not have permission to create tables. The generated name is returned in QUALIFIED_PROJECTION_NAME. Supported values: The default value is FALSE.
        • COLLECTION_NAME: [DEPRECATED--please specify the containing schema for the projection as part of projectionName and use GPUdb.createSchema to create the schema if non-existent] Name of a schema for the projection. If the schema is non-existent, it will be automatically created. The default value is ''.
        • EXPRESSION: An optional filter expression to be applied to the source table prior to the projection. The default value is ''.
        • IS_REPLICATED: If TRUE then the projection will be replicated even if the source table is not. Supported values: The default value is FALSE.
        • OFFSET: The number of initial results to skip (this can be useful for paging through the results). The default value is '0'.
        • LIMIT: The number of records to keep. The default value is '-9999'.
        • ORDER_BY: Comma-separated list of the columns to be sorted by; e.g. 'timestamp asc, x desc'. The columns specified must be present in columnNames. If any alias is given for any column name, the alias must be used, rather than the original column name. The default value is ''.
        • CHUNK_SIZE: Indicates the number of records per chunk to be used for this projection.
        • CHUNK_COLUMN_MAX_MEMORY: Indicates the target maximum data size for each column in a chunk to be used for this projection.
        • CHUNK_MAX_MEMORY: Indicates the target maximum data size for all columns in a chunk to be used for this projection.
        • CREATE_INDEXES: Comma-separated list of columns on which to create indexes on the projection. The columns specified must be present in columnNames. If any alias is given for any column name, the alias must be used, rather than the original column name.
        • TTL: Sets the TTL of the projection specified in projectionName.
        • SHARD_KEY: Comma-separated list of the columns to be sharded on; e.g. 'column1, column2'. The columns specified must be present in columnNames. If any alias is given for any column name, the alias must be used, rather than the original column name. The default value is ''.
        • PERSIST: If TRUE, then the projection specified in projectionName will be persisted and will not expire unless a TTL is specified. If FALSE, then the projection will be an in-memory table and will expire unless a TTL is specified otherwise. Supported values: The default value is FALSE.
        • PRESERVE_DICT_ENCODING: If TRUE, then columns that were dict encoded in the source table will be dict encoded in the projection. Supported values: The default value is TRUE.
        • RETAIN_PARTITIONS: Determines whether the created projection will retain the partitioning scheme from the source table. Supported values: The default value is FALSE.
        • PARTITION_TYPE: Partitioning scheme to use. Supported values:
        • PARTITION_KEYS: Comma-separated list of partition keys, which are the columns or column expressions by which records will be assigned to partitions defined by PARTITION_DEFINITIONS.
        • PARTITION_DEFINITIONS: Comma-separated list of partition definitions, whose format depends on the choice of PARTITION_TYPE. See range partitioning, interval partitioning, list partitioning, hash partitioning, or series partitioning for example formats.
        • IS_AUTOMATIC_PARTITION: If TRUE, a new partition will be created for values which don't fall into an existing partition. Currently only supported for list partitions. Supported values: The default value is FALSE.
        • VIEW_ID: ID of view of which this projection is a member. The default value is ''.
        • STRATEGY_DEFINITION: The tier strategy for the table and its columns.
        • COMPRESSION_CODEC: The default compression codec for the projection's columns.
        • JOIN_WINDOW_FUNCTIONS: If set, window functions which require a reshard will be computed separately and joined back together, if the width of the projection is greater than the join_window_functions_threshold. The default value is 'true'.
        • JOIN_WINDOW_FUNCTIONS_THRESHOLD: If the projection is greater than this width (in bytes), then window functions which require a reshard will be computed separately and joined back together. The default value is ''.
        The default value is an empty Map.

    • Method Detail

      • getClassSchema

        public static org.apache.avro.Schema getClassSchema()
        This method supports the Avro framework and is not intended to be called directly by the user.
        Returns:
        The schema for the class.

      • getTableName

        public String getTableName()
        Name of the existing table on which the projection is to be applied, in [schema_name.]table_name format, using standard name resolution rules. An empty table name creates a projection from a single-row virtual table, where columns specified should be constants or constant expressions.
        Returns:
        The current value of tableName.

      • setTableName

        public CreateProjectionRequest setTableName​(String tableName)
        Name of the existing table on which the projection is to be applied, in [schema_name.]table_name format, using standard name resolution rules. An empty table name creates a projection from a single-row virtual table, where columns specified should be constants or constant expressions.
        Parameters:
        tableName - The new value for tableName.
        Returns:
        this to mimic the builder pattern.

      • getProjectionName

        public String getProjectionName()
        Name of the projection to be created, in [schema_name.]table_name format, using standard name resolution rules and meeting table naming criteria.
        Returns:
        The current value of projectionName.

      • getColumnNames

        public List<String> getColumnNames()
        List of columns from tableName to be included in the projection. Can include derived columns. Can be specified as aliased via the syntax 'column_name as alias'.
        Returns:
        The current value of columnNames.

      • setColumnNames

        public CreateProjectionRequest setColumnNames​(List<String> columnNames)
        List of columns from tableName to be included in the projection. Can include derived columns. Can be specified as aliased via the syntax 'column_name as alias'.
        Parameters:
        columnNames - The new value for columnNames.
        Returns:
        this to mimic the builder pattern.

      • getSchema

        public org.apache.avro.Schema getSchema()
        This method supports the Avro framework and is not intended to be called directly by the user.
        Specified by:
        getSchema in interface org.apache.avro.generic.GenericContainer
        Returns:
        The schema object describing this class.

      • get

        public Object get​(int index)
        This method supports the Avro framework and is not intended to be called directly by the user.
        Specified by:
        get in interface org.apache.avro.generic.IndexedRecord
        Parameters:
        index - the position of the field to get
        Returns:
        value of the field with the given index.
        Throws:
        IndexOutOfBoundsException

      • put

        public void put​(int index,
                Object value)
        This method supports the Avro framework and is not intended to be called directly by the user.
        Specified by:
        put in interface org.apache.avro.generic.IndexedRecord
        Parameters:
        index - the position of the field to set
        value - the value to set
        Throws:
        IndexOutOfBoundsException

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class Object