/** Initialize the scan, returning false if there was some error. */
public boolean init(TransactionManager tran) throws StandardException {
if (SanityManager.DEBUG) {
// We really expect to have at least one
// merge run.
SanityManager.ASSERT(mergeRuns != null);
SanityManager.ASSERT(mergeRuns.size() > 0);
// This sort scan also expects that the
// caller has ensured that the sort buffer
// capacity will hold a row from all the
// merge runs.
SanityManager.ASSERT(sortBuffer.capacity() >= mergeRuns.size());
}
// Clear the sort buffer.
sortBuffer.reset();
// Create an array to hold a scan controller
// for each merge run.
openScans = new StreamContainerHandle[mergeRuns.size()];
if (openScans == null) return false;
// Open a scan on each merge run.
int scanindex = 0;
Enumeration e = mergeRuns.elements();
while (e.hasMoreElements()) {
// get the container id
long id = ((Long) e.nextElement()).longValue();
Transaction rawTran = tran.getRawStoreXact(); // get raw transaction
int segmentId = StreamContainerHandle.TEMPORARY_SEGMENT;
openScans[scanindex++] = rawTran.openStreamContainer(segmentId, id, hold);
}
// Load the initial rows.
for (scanindex = 0; scanindex < openScans.length; scanindex++) mergeARow(scanindex);
// Success!
return true;
}
/**
* Create an empty secondary index b-tree, using the generic b-tree to do the generic part of the
* creation process.
*
* <p>This routine opens the newly created container, adds a single page, and makes this page the
* root by inserting a LeafControlRow onto this page at slot 0 and marking in that control row
* that the page is a root page.
*
* <p>The following properties are specific to the b-tree secondary index:
*
* <UL>
* <LI>"baseConglomerateId" (integer). The conglomerate id of the base conglomerate is never
* actually accessed by the b-tree secondary index implementation, it only serves as a
* namespace for row locks. This property is required.
* <LI>"rowLocationColumn" (integer). The zero-based index into the row which the b-tree
* secondary index will assume holds a @see RowLocation of the base row in the base
* conglomerate. This value will be used for acquiring locks. In this implementation
* RowLocationColumn must be the last key column. This property is required.
* </UL>
*
* A secondary index i (a, b) on table t (a, b, c) would have rows which looked like (a, b,
* row_location). baseConglomerateId is set to the conglomerate id of t. rowLocationColumns is set
* to 2. allowsDuplicates would be set to false, @see BTree#create. To create a unique secondary
* index set uniquenessColumns to 2, this means that the btree code will compare the key values
* but not the row id when determing uniqueness. To create a nonunique secondary index set
* uniquenessColumns to 3, this would mean that the uniqueness test would include the row location
* and since all row locations will be unique all rows inserted into the index will be
* differentiated (at least) by row location.
*
* @see BTree#create
* @exception StandardException Standard exception policy.
*/
public void create(
TransactionManager xact_manager,
int segmentId,
long input_conglomid,
DataValueDescriptor[] template,
ColumnOrdering[] columnOrder,
int[] collationIds,
Properties properties,
int temporaryFlag)
throws StandardException {
String property_value = null;
Transaction rawtran = xact_manager.getRawStoreXact();
if (properties == null) {
throw (StandardException.newException(
SQLState.BTREE_PROPERTY_NOT_FOUND, PROPERTY_BASECONGLOMID));
}
// Get baseConglomerateId //
property_value = properties.getProperty(PROPERTY_BASECONGLOMID);
if (property_value == null) {
throw (StandardException.newException(
SQLState.BTREE_PROPERTY_NOT_FOUND, PROPERTY_BASECONGLOMID));
}
if (SanityManager.DEBUG) {
if (property_value == null)
SanityManager.THROWASSERT(PROPERTY_BASECONGLOMID + "property not passed to B2I.create()");
}
baseConglomerateId = Long.parseLong(property_value);
// Get rowLocationColumn //
property_value = properties.getProperty(PROPERTY_ROWLOCCOLUMN);
if (SanityManager.DEBUG) {
if (property_value == null)
SanityManager.THROWASSERT(PROPERTY_ROWLOCCOLUMN + "property not passed to B2I.create()");
}
if (property_value == null) {
throw (StandardException.newException(
SQLState.BTREE_PROPERTY_NOT_FOUND, PROPERTY_BASECONGLOMID));
}
rowLocationColumn = Integer.parseInt(property_value);
// Currently the row location column must be the last column (makes)
// comparing the columns in the index easier.
if (SanityManager.DEBUG) {
SanityManager.ASSERT(
rowLocationColumn == template.length - 1,
"rowLocationColumn is not the last column in the index");
SanityManager.ASSERT(template[rowLocationColumn] instanceof RowLocation);
// There must be at least one key column
if (rowLocationColumn < 1)
SanityManager.THROWASSERT(
"rowLocationColumn (" + rowLocationColumn + ") expected to be >= 1");
}
/* convert the sorting order information into a boolean array map.
* If the sorting order for the columns is not provided, we
* assign the default as Ascending Order.
* array length is equal to template length, because column order
* length changes whether it is unique or is non unique. store assumes
* template length arrays. So, we make template length array and make
* the last column as ascending instead of having lot of execeptions
* code.
*/
ascDescInfo = new boolean[template.length];
for (int i = 0; i < ascDescInfo.length; i++) {
if (columnOrder != null && i < columnOrder.length)
ascDescInfo[i] = columnOrder[i].getIsAscending();
else ascDescInfo[i] = true; // default values - ascending order
}
// get collation ids from input collation ids, store it in the
// conglom state.
collation_ids = ConglomerateUtil.createCollationIds(template.length, collationIds);
hasCollatedTypes = hasCollatedColumns(collation_ids);
// Do the generic part of creating the b-tree.
super.create(
rawtran,
segmentId,
input_conglomid,
template,
properties,
getTypeFormatId(),
temporaryFlag);
// open the base conglomerate - to get the lock
ConglomerateController base_cc =
xact_manager.openConglomerate(
baseConglomerateId,
false,
TransactionController.OPENMODE_FOR_LOCK_ONLY,
TransactionController.MODE_TABLE,
TransactionController.ISOLATION_SERIALIZABLE);
OpenBTree open_btree = new OpenBTree();
BTreeLockingPolicy b2i_locking_policy =
new B2ITableLocking3(
rawtran,
TransactionController.MODE_TABLE,
rawtran.newLockingPolicy(
LockingPolicy.MODE_CONTAINER, TransactionController.ISOLATION_SERIALIZABLE, true),
base_cc,
open_btree);
// The following call will "open" the new btree. Create is
// an interesting case. What we really want is read only table lock
// on the base conglomerate and update locks on the index. For now
// just get the update lock on the base table, this is done by the
// lockTable() call made by base class.
open_btree.init(
(TransactionManager) xact_manager, // current user xact
(TransactionManager) xact_manager, // current xact
(ContainerHandle) null, // have init open the container.
rawtran,
false,
(ContainerHandle.MODE_FORUPDATE),
TransactionController.MODE_TABLE,
b2i_locking_policy, // get table level lock.
this,
(LogicalUndo) null, // no logical undo necessary, as
// initEmptyBtree()
// work will be done single user and
// rows will not move.
(DynamicCompiledOpenConglomInfo) null);
// Open the newly created container, and insert the first control row.
LeafControlRow.initEmptyBtree(open_btree);
open_btree.close();
base_cc.close();
}
/**
* Create a new btree locking policy from scratch.
*
* @exception StandardException Standard exception policy.
*/
protected BTreeLockingPolicy getBtreeLockingPolicy(
Transaction rawtran,
int lock_level,
int mode,
int isolation_level,
ConglomerateController base_cc,
OpenBTree open_btree)
throws StandardException {
BTreeLockingPolicy ret_locking_policy = null;
if (SanityManager.DEBUG) {
SanityManager.ASSERT(
(isolation_level == TransactionController.ISOLATION_SERIALIZABLE)
|| (isolation_level == TransactionController.ISOLATION_REPEATABLE_READ)
|| (isolation_level == TransactionController.ISOLATION_READ_COMMITTED_NOHOLDLOCK)
|| (isolation_level == TransactionController.ISOLATION_READ_COMMITTED)
|| (isolation_level == TransactionController.ISOLATION_READ_UNCOMMITTED),
"bad isolation_level = " + isolation_level);
}
if (lock_level == TransactionController.MODE_TABLE) {
ret_locking_policy =
new B2ITableLocking3(
rawtran,
lock_level,
rawtran.newLockingPolicy(LockingPolicy.MODE_CONTAINER, isolation_level, true),
base_cc,
open_btree);
} else if (lock_level == TransactionController.MODE_RECORD) {
if (isolation_level == TransactionController.ISOLATION_SERIALIZABLE) {
ret_locking_policy =
new B2IRowLocking3(
rawtran,
lock_level,
rawtran.newLockingPolicy(LockingPolicy.MODE_RECORD, isolation_level, true),
base_cc,
open_btree);
} else if ((isolation_level == TransactionController.ISOLATION_REPEATABLE_READ)) {
ret_locking_policy =
new B2IRowLockingRR(
rawtran,
lock_level,
rawtran.newLockingPolicy(LockingPolicy.MODE_RECORD, isolation_level, true),
base_cc,
open_btree);
} else if ((isolation_level == TransactionController.ISOLATION_READ_COMMITTED)
|| (isolation_level == TransactionController.ISOLATION_READ_COMMITTED_NOHOLDLOCK)) {
ret_locking_policy =
new B2IRowLocking2(
rawtran,
lock_level,
rawtran.newLockingPolicy(LockingPolicy.MODE_RECORD, isolation_level, true),
base_cc,
open_btree);
} else if (isolation_level == TransactionController.ISOLATION_READ_UNCOMMITTED) {
ret_locking_policy =
new B2IRowLocking1(
rawtran,
lock_level,
rawtran.newLockingPolicy(LockingPolicy.MODE_RECORD, isolation_level, true),
base_cc,
open_btree);
}
}
if (SanityManager.DEBUG) {
SanityManager.ASSERT(ret_locking_policy != null, "ret_locking_policy == null");
}
return (ret_locking_policy);
}
