quasardb C API
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Data Structures | Functions
Batch functions

Data Structures

struct  int_put_update_t
 The required parameters for an integer operation within a batch. More...
 
struct  blob_put_update_t
 The required parameters for a blob put or update operations within a batch. More...
 
struct  string_put_update_t
 The required parameters for a string put or update operations within a batch. More...
 
struct  double_put_update_t
 The required parameters for a double operation within a batch. More...
 
struct  timestamp_put_update_t
 The required parameters for a timestamp operation within a batch. More...
 
struct  qdb_operation_t
 A single operation containing all parameters to execute the operation in a batch or in a transaction. More...
 

Functions

QDB_API_LINKAGE qdb_error_t qdb_init_operations (qdb_operation_t *operations, size_t operation_count)
 Initializes an array of qdb_operation_t.
 
QDB_API_LINKAGE qdb_error_t qdb_coalesce_operations (qdb_handle_t handle, qdb_operation_t *operations, size_t operation_count, qdb_operation_t **coalesced_operations, size_t *coalesced_operation_count)
 Coalesces an array of qdb_operation_t.
 
QDB_API_LINKAGE size_t qdb_run_batch (qdb_handle_t handle, qdb_operation_t *operations, size_t operation_count)
 Runs the operations in batch.
 
QDB_API_LINKAGE qdb_error_t qdb_run_transaction (qdb_handle_t handle, qdb_operation_t *operations, size_t operation_count, size_t *failure_index)
 Runs the operations in a single transaction.
 

Detailed Description

Function Documentation

◆ qdb_coalesce_operations()

QDB_API_LINKAGE qdb_error_t qdb_coalesce_operations ( qdb_handle_t  handle,
qdb_operation_t *  operations,
size_t  operation_count,
qdb_operation_t **  coalesced_operations,
size_t *  coalesced_operation_count 
)

Coalesces an array of qdb_operation_t.

Use this function to minimize operations to a given entry by omiting redundant operations, combining multiple write operations, and resolving known read operations.

After this function has been called, operations in the input array that were resolved locally will have an error code indicating success. The remaining input operations will have qdb_e_skipped as error code, and their effects will be subsumed by operations in the output array of coalesced operations. All operations are assumed to succeed, if a coalesced operation fails locally resolved operations on the same entry are considered invalid.

This function allocates memory for the array of coalesced operations, call qdb_release on the coalesced_operations array to release memory.

Parameters
handleA valid handle previously initialized by qdb_open or qdb_open_tcp.
operationsA pointer to a correctly constructed array of operations
operation_countThe number of elements in the array of operations
coalesced_operationsA pointer to the array of coalesced operations
coalesced_operation_countA pointer to the number of elements in the array of coalesced operations
Returns
A qdb_error_t code indicating success or failure.
See also
qdb_operation_t, qdb_run_batch, qdb_release

◆ qdb_init_operations()

QDB_API_LINKAGE qdb_error_t qdb_init_operations ( qdb_operation_t *  operations,
size_t  operation_count 
)

Initializes an array of qdb_operation_t.

Use this function to make sure all the fields of the operation structure are properly initialized to their default values.

After this function has been called, the user must then set the required parameter for each operation.

Parameters
operationsA pointer to an array of operations
operation_countThe number of elements in the array of operations
Returns
A qdb_error_t code indicating success or failure.
See also
qdb_operation_t

◆ qdb_run_batch()

QDB_API_LINKAGE size_t qdb_run_batch ( qdb_handle_t  handle,
qdb_operation_t *  operations,
size_t  operation_count 
)

Runs the operations in batch.

When operations are run in batch the order of execution is optimized for speed and each operation is run independently.

Running operations is batch is generally the best way to achieve a very high level of performance, especially for bulk loading of data. That's because batches minimize network communication and organize the order of execution for maximum throughput.

If one or several operations within the batch fail, the rest of the batch isn't affected.

If one or several operations within the batch is ill-formed, the whole batch will be aborted. An ill formed operation is for example an operation missing a parameter.

Each operation will result a result according to its type.

After a batch has been run (successful or not), the user must call qdb_release on the operations pointer to release all API-allocated buffers.

For an ordered, transactional "all or nothing" behavior use qdb_run_transaction.

Parameters
handleA valid handle previously initialized by qdb_open or qdb_open_tcp.
operationsA pointer to a correctly constructed array of operations
operation_countThe number of elements in the array of operations
Returns
The number of successful operations in the batch.
See also
qdb_operation_t, qdb_run_transaction, qdb_release

◆ qdb_run_transaction()

QDB_API_LINKAGE qdb_error_t qdb_run_transaction ( qdb_handle_t  handle,
qdb_operation_t *  operations,
size_t  operation_count,
size_t *  failure_index 
)

Runs the operations in a single transaction.

Operations that run in a transaction will be executed ordered to preserve the logic of the transaction and if an error occurred the previously executed operations will be rolled back.

The operation is committed if and only if all operations have been successful.

The result of the transaction is not visible by other clients until it has been committed.

After a transaction has been run (successful or not), the user must call qdb_release on operations to release all API-allocated buffers.

Use transactions when integrity and order is paramount. For maximum performances consider using batches (qdb_run_batch).

Parameters
handleA valid handle previously initialized by qdb_open or qdb_open_tcp.
operationsA pointer to a correctly constructed array of operations
operation_countThe number of elements in the array of operations
failure_indexA pointer to the index of the first failed operation
Returns
A qdb_error_t code indicating success or failure.
See also
qdb_operation_t, qdb_run_batch, qdb_release