Method dropTableImpl

src/Databases/DatabaseAtomic.cpp:207–242

}

void DatabaseAtomic::dropTableImpl(ContextPtr local_context, const String & table_name, bool sync)
{
    String table_metadata_path = getObjectMetadataPath(table_name);
    String table_metadata_path_drop;
    StoragePtr table;
    auto db_disk = getDisk();
    {
        std::lock_guard lock(mutex);
        table = getTableUnlocked(table_name);
        table_metadata_path_drop = DatabaseCatalog::instance().getPathForDroppedMetadata(table->getStorageID());

        db_disk->createDirectories(fs::path(table_metadata_path_drop).parent_path());

        auto txn = local_context->getZooKeeperMetadataTransaction();
        if (txn && !local_context->isInternalSubquery())
            txn->commit();      /// Commit point (a sort of) for Replicated database

        /// NOTE: replica will be lost if server crashes before the following rename
        /// We apply changes in ZooKeeper before applying changes in local metadata file
        /// to reduce probability of failures between these operations
        /// (it's more likely to lost connection, than to fail before applying local changes).
        /// TODO better detection and recovery

        db_disk->replaceFile(table_metadata_path, table_metadata_path_drop); /// Mark table as dropped
        DatabaseOrdinary::detachTableUnlocked(table_name);  /// Should never throw
        table_name_to_path.erase(table_name);
        snapshot_detached_tables.erase(table_name);
    }

    if (table->storesDataOnDisk())
        tryRemoveSymlink(table_name);

    /// Notify DatabaseCatalog that table was dropped. It will remove table data in background.
    /// Cleanup is performed outside of database to allow easily DROP DATABASE without waiting for cleanup to complete.
    DatabaseCatalog::instance().enqueueDroppedTableCleanup(table->getStorageID(), table, db_disk, table_metadata_path_drop, sync);
}

void DatabaseAtomic::renameTable(ContextPtr local_context, const String & table_name, IDatabase & to_database,
                                 const String & to_table_name, bool exchange, bool dictionary)