public class CreateChangelogViewProcedure
extends java.lang.Object
The procedure removes the carry-over rows by default. If you want to keep them, you can set "remove_carryovers" to be false in the options.
The procedure doesn't compute the pre/post update images by default. If you want to compute them, you can set "compute_updates" to be true in the options.
Carry-over rows are the result of a removal and insertion of the same row within an operation because of the copy-on-write mechanism. For example, given a file which contains row1 (id=1, data='a') and row2 (id=2, data='b'). A copy-on-write delete of row2 would require erasing this file and preserving row1 in a new file. The changelog table would report this as (id=1, data='a', op='DELETE') and (id=1, data='a', op='INSERT'), despite it not being an actual change to the table. The procedure finds the carry-over rows and removes them from the result.
Pre/post update images are converted from a pair of a delete row and an insert row. Identifier columns are used for determining whether an insert and a delete record refer to the same row. If the two records share the same values for the identity columns they are considered to be before and after states of the same row. You can either set identifier fields in the table schema or input them as the procedure parameters. Here is an example of pre/post update images with an identifier column(id). A pair of a delete row and an insert row with the same id:
will be marked as pre/post update images:
Modifier and Type | Class and Description |
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protected static class |
org.apache.iceberg.spark.procedures.BaseProcedure.Builder<T extends org.apache.iceberg.spark.procedures.BaseProcedure> |
Modifier and Type | Field and Description |
---|---|
protected static org.apache.spark.sql.types.DataType |
STRING_ARRAY |
protected static org.apache.spark.sql.types.DataType |
STRING_MAP |
Modifier and Type | Method and Description |
---|---|
protected SparkActions |
actions() |
static SparkProcedures.ProcedureBuilder |
builder() |
org.apache.spark.sql.catalyst.InternalRow[] |
call(org.apache.spark.sql.catalyst.InternalRow args)
Executes this procedure.
|
protected void |
closeService()
Closes this procedure's executor service if a new one was created with
executorService(int, String) . |
java.lang.String |
description()
Returns the description of this procedure.
|
protected java.util.concurrent.ExecutorService |
executorService(int threadPoolSize,
java.lang.String nameFormat)
Starts a new executor service which can be used by this procedure in its work.
|
protected org.apache.spark.sql.Dataset<org.apache.spark.sql.Row> |
loadRows(org.apache.spark.sql.connector.catalog.Identifier tableIdent,
java.util.Map<java.lang.String,java.lang.String> options) |
protected SparkTable |
loadSparkTable(org.apache.spark.sql.connector.catalog.Identifier ident) |
protected <T> T |
modifyIcebergTable(org.apache.spark.sql.connector.catalog.Identifier ident,
java.util.function.Function<Table,T> func) |
protected org.apache.spark.sql.catalyst.InternalRow |
newInternalRow(java.lang.Object... values) |
org.apache.spark.sql.types.StructType |
outputType()
Returns the type of rows produced by this procedure.
|
ProcedureParameter[] |
parameters()
Returns the input parameters of this procedure.
|
protected void |
refreshSparkCache(org.apache.spark.sql.connector.catalog.Identifier ident,
org.apache.spark.sql.connector.catalog.Table table) |
protected org.apache.spark.sql.SparkSession |
spark() |
protected org.apache.spark.sql.connector.catalog.TableCatalog |
tableCatalog() |
protected Spark3Util.CatalogAndIdentifier |
toCatalogAndIdentifier(java.lang.String identifierAsString,
java.lang.String argName,
org.apache.spark.sql.connector.catalog.CatalogPlugin catalog) |
protected org.apache.spark.sql.connector.catalog.Identifier |
toIdentifier(java.lang.String identifierAsString,
java.lang.String argName) |
protected <T> T |
withIcebergTable(org.apache.spark.sql.connector.catalog.Identifier ident,
java.util.function.Function<Table,T> func) |
protected static final org.apache.spark.sql.types.DataType STRING_MAP
protected static final org.apache.spark.sql.types.DataType STRING_ARRAY
public static SparkProcedures.ProcedureBuilder builder()
public ProcedureParameter[] parameters()
Procedure
public org.apache.spark.sql.types.StructType outputType()
Procedure
public org.apache.spark.sql.catalyst.InternalRow[] call(org.apache.spark.sql.catalyst.InternalRow args)
Procedure
Spark will align the provided arguments according to the input parameters defined in Procedure.parameters()
either by position or by name before execution.
Implementations may provide a summary of execution by returning one or many rows as a
result. The schema of output rows must match the defined output type in Procedure.outputType()
.
args
- input argumentspublic java.lang.String description()
Procedure
protected org.apache.spark.sql.SparkSession spark()
protected SparkActions actions()
protected org.apache.spark.sql.connector.catalog.TableCatalog tableCatalog()
protected <T> T modifyIcebergTable(org.apache.spark.sql.connector.catalog.Identifier ident, java.util.function.Function<Table,T> func)
protected <T> T withIcebergTable(org.apache.spark.sql.connector.catalog.Identifier ident, java.util.function.Function<Table,T> func)
protected org.apache.spark.sql.connector.catalog.Identifier toIdentifier(java.lang.String identifierAsString, java.lang.String argName)
protected Spark3Util.CatalogAndIdentifier toCatalogAndIdentifier(java.lang.String identifierAsString, java.lang.String argName, org.apache.spark.sql.connector.catalog.CatalogPlugin catalog)
protected SparkTable loadSparkTable(org.apache.spark.sql.connector.catalog.Identifier ident)
protected org.apache.spark.sql.Dataset<org.apache.spark.sql.Row> loadRows(org.apache.spark.sql.connector.catalog.Identifier tableIdent, java.util.Map<java.lang.String,java.lang.String> options)
protected void refreshSparkCache(org.apache.spark.sql.connector.catalog.Identifier ident, org.apache.spark.sql.connector.catalog.Table table)
protected org.apache.spark.sql.catalyst.InternalRow newInternalRow(java.lang.Object... values)
protected void closeService()
executorService(int, String)
. Does not block for any remaining tasks.protected java.util.concurrent.ExecutorService executorService(int threadPoolSize, java.lang.String nameFormat)
withIcebergTable(Identifier, Function)
or modifyIcebergTable(Identifier, Function)
are called. If these methods are not used then the
service can be shut down with closeService()
or left to be closed when this class is
finalized.threadPoolSize
- number of threads in the servicenameFormat
- name prefix for threads created in this service