Package org.apache.iceberg

Interface OverwriteFiles

  • All Superinterfaces:
    PendingUpdate<Snapshot>, SnapshotUpdate<OverwriteFiles>
    All Known Implementing Classes:
    BaseOverwriteFiles
    public interface OverwriteFiles
extends SnapshotUpdate<OverwriteFiles>
    API for overwriting files in a table.

    This API accumulates file additions and produces a new Snapshot of the table by replacing all the deleted files with the set of additions. This operation is used to implement idempotent writes that always replace a section of a table with new data or update/delete operations that eagerly overwrite files.

    Overwrites can be validated. The default validation mode is idempotent, meaning the overwrite is correct and should be committed out regardless of other concurrent changes to the table. For example, this can be used for replacing all the data for day D with query results. Alternatively, this API can be configured for overwriting certain files with their filtered versions while ensuring no new data that would need to be filtered has been added.

    When committing, these changes will be applied to the latest table snapshot. Commit conflicts will be resolved by applying the changes to the new latest snapshot and reattempting the commit.

    • Method Detail

      • overwriteByRowFilter

        OverwriteFiles overwriteByRowFilter​(Expression expr)
        Delete files that match an Expression on data rows from the table.

        A file is selected to be deleted by the expression if it could contain any rows that match the expression (candidate files are selected using an inclusive projection). These candidate files are deleted if all of the rows in the file must match the expression (the partition data matches the expression's Projections.strict(PartitionSpec) strict projection}). This guarantees that files are deleted if and only if all rows in the file must match the expression.

        Files that may contain some rows that match the expression and some rows that do not will result in a ValidationException.

        Parameters:
        expr - an expression on rows in the table
        Returns:
        this for method chaining
        Throws:
        ValidationException - If a file can contain both rows that match and rows that do not

      • deleteFile

        OverwriteFiles deleteFile​(DataFile file)
        Delete a DataFile from the table.
        Parameters:
        file - a data file
        Returns:
        this for method chaining

      • validateAddedFilesMatchOverwriteFilter

        OverwriteFiles validateAddedFilesMatchOverwriteFilter()
        Signal that each file added to the table must match the overwrite expression.

        If this method is called, each added file is validated on commit to ensure that it matches the overwrite row filter. This is used to ensure that writes are idempotent: that files cannot be added during a commit that would not be removed if the operation were run a second time.

        Returns:
        this for method chaining

      • validateNoConflictingAppends

        OverwriteFiles validateNoConflictingAppends​(java.lang.Long readSnapshotId,
                                            Expression conflictDetectionFilter)
        Enables validation that files added concurrently do not conflict with this commit's operation.

        This method should be called when the table is queried to determine which files to delete/append. If a concurrent operation commits a new file after the data was read and that file might contain rows matching the specified conflict detection filter, the overwrite operation will detect this during retries and fail.

        Calling this method with a correct conflict detection filter is required to maintain serializable isolation for eager update/delete operations. Otherwise, the isolation level will be snapshot isolation.

        Parameters:
        readSnapshotId - the snapshot id that was used to read the data or null if the table was empty
        conflictDetectionFilter - an expression on rows in the table
        Returns:
        this for method chaining