Examples with Column org.h2.table.Column used on opensource projects

Example 56 with Column

use of org.h2.table.Column in project h2database by h2database.

the class TableFunction method getTable.

private ValueResultSet getTable(Session session, Expression[] argList, boolean onlyColumnList, boolean distinctRows) {
    int len = columnList.length;
    Expression[] header = new Expression[len];
    Database db = session.getDatabase();
    for (int i = 0; i < len; i++) {
        Column c = columnList[i];
        ExpressionColumn col = new ExpressionColumn(db, c);
        header[i] = col;
    }
    LocalResult result = new LocalResult(session, header, len);
    if (distinctRows) {
        result.setDistinct();
    }
    if (!onlyColumnList) {
        Value[][] list = new Value[len][];
        int rows = 0;
        for (int i = 0; i < len; i++) {
            Value v = argList[i].getValue(session);
            if (v == ValueNull.INSTANCE) {
                list[i] = new Value[0];
            } else {
                ValueArray array = (ValueArray) v.convertTo(Value.ARRAY);
                Value[] l = array.getList();
                list[i] = l;
                rows = Math.max(rows, l.length);
            }
        }
        for (int row = 0; row < rows; row++) {
            Value[] r = new Value[len];
            for (int j = 0; j < len; j++) {
                Value[] l = list[j];
                Value v;
                if (l.length <= row) {
                    v = ValueNull.INSTANCE;
                } else {
                    Column c = columnList[j];
                    v = l[row];
                    v = c.convert(v);
                    v = v.convertPrecision(c.getPrecision(), false);
                    v = v.convertScale(true, c.getScale());
                }
                r[j] = v;
            }
            result.addRow(r);
        }
    }
    result.done();
    return ValueResultSet.get(getSimpleResultSet(result, Integer.MAX_VALUE));
}

Example 57 with Column

use of org.h2.table.Column in project h2database by h2database.

the class FullText method parseKey.

/**
 * Parse a primary key condition into the primary key columns.
 *
 * @param conn the database connection
 * @param key the primary key condition as a string
 * @return an array containing the column name list and the data list
 */
protected static Object[][] parseKey(Connection conn, String key) {
    ArrayList<String> columns = New.arrayList();
    ArrayList<String> data = New.arrayList();
    JdbcConnection c = (JdbcConnection) conn;
    Session session = (Session) c.getSession();
    Parser p = new Parser(session);
    Expression expr = p.parseExpression(key);
    addColumnData(columns, data, expr);
    Object[] col = columns.toArray();
    Object[] dat = data.toArray();
    Object[][] columnData = { col, dat };
    return columnData;
}

Example 58 with Column

use of org.h2.table.Column in project h2database by h2database.

the class AggregateDataMedian method getMedianColumnIndex.

/**
 * Get the index (if any) for the column specified in the median aggregate.
 *
 * @param on the expression (usually a column expression)
 * @return the index, or null
 */
static Index getMedianColumnIndex(Expression on) {
    if (on instanceof ExpressionColumn) {
        ExpressionColumn col = (ExpressionColumn) on;
        Column column = col.getColumn();
        TableFilter filter = col.getTableFilter();
        if (filter != null) {
            Table table = filter.getTable();
            ArrayList<Index> indexes = table.getIndexes();
            Index result = null;
            if (indexes != null) {
                boolean nullable = column.isNullable();
                for (int i = 1, size = indexes.size(); i < size; i++) {
                    Index index = indexes.get(i);
                    if (!index.canFindNext()) {
                        continue;
                    }
                    if (!index.isFirstColumn(column)) {
                        continue;
                    }
                    // Prefer index without nulls last for nullable columns
                    if (result == null || result.getColumns().length > index.getColumns().length || nullable && isNullsLast(result) && !isNullsLast(index)) {
                        result = index;
                    }
                }
            }
            return result;
        }
    }
    return null;
}

Example 59 with Column

use of org.h2.table.Column in project h2database by h2database.

the class BaseIndex method getCostRangeIndex.

/**
 * Calculate the cost for the given mask as if this index was a typical
 * b-tree range index. This is the estimated cost required to search one
 * row, and then iterate over the given number of rows.
 *
 * @param masks the IndexCondition search masks, one for each column in the
 *            table
 * @param rowCount the number of rows in the index
 * @param filters all joined table filters
 * @param filter the current table filter index
 * @param sortOrder the sort order
 * @param isScanIndex whether this is a "table scan" index
 * @param allColumnsSet the set of all columns
 * @return the estimated cost
 */
protected final long getCostRangeIndex(int[] masks, long rowCount, TableFilter[] filters, int filter, SortOrder sortOrder, boolean isScanIndex, HashSet<Column> allColumnsSet) {
    rowCount += Constants.COST_ROW_OFFSET;
    int totalSelectivity = 0;
    long rowsCost = rowCount;
    if (masks != null) {
        for (int i = 0, len = columns.length; i < len; i++) {
            Column column = columns[i];
            int index = column.getColumnId();
            int mask = masks[index];
            if ((mask & IndexCondition.EQUALITY) == IndexCondition.EQUALITY) {
                if (i == columns.length - 1 && getIndexType().isUnique()) {
                    rowsCost = 3;
                    break;
                }
                totalSelectivity = 100 - ((100 - totalSelectivity) * (100 - column.getSelectivity()) / 100);
                long distinctRows = rowCount * totalSelectivity / 100;
                if (distinctRows <= 0) {
                    distinctRows = 1;
                }
                rowsCost = 2 + Math.max(rowCount / distinctRows, 1);
            } else if ((mask & IndexCondition.RANGE) == IndexCondition.RANGE) {
                rowsCost = 2 + rowCount / 4;
                break;
            } else if ((mask & IndexCondition.START) == IndexCondition.START) {
                rowsCost = 2 + rowCount / 3;
                break;
            } else if ((mask & IndexCondition.END) == IndexCondition.END) {
                rowsCost = rowCount / 3;
                break;
            } else {
                break;
            }
        }
    }
    // If the ORDER BY clause matches the ordering of this index,
    // it will be cheaper than another index, so adjust the cost
    // accordingly.
    long sortingCost = 0;
    if (sortOrder != null) {
        sortingCost = 100 + rowCount / 10;
    }
    if (sortOrder != null && !isScanIndex) {
        boolean sortOrderMatches = true;
        int coveringCount = 0;
        int[] sortTypes = sortOrder.getSortTypes();
        TableFilter tableFilter = filters == null ? null : filters[filter];
        for (int i = 0, len = sortTypes.length; i < len; i++) {
            if (i >= indexColumns.length) {
                // more of the order by columns.
                break;
            }
            Column col = sortOrder.getColumn(i, tableFilter);
            if (col == null) {
                sortOrderMatches = false;
                break;
            }
            IndexColumn indexCol = indexColumns[i];
            if (!col.equals(indexCol.column)) {
                sortOrderMatches = false;
                break;
            }
            int sortType = sortTypes[i];
            if (sortType != indexCol.sortType) {
                sortOrderMatches = false;
                break;
            }
            coveringCount++;
        }
        if (sortOrderMatches) {
            // "coveringCount" makes sure that when we have two
            // or more covering indexes, we choose the one
            // that covers more.
            sortingCost = 100 - coveringCount;
        }
    }
    // If we have two indexes with the same cost, and one of the indexes can
    // satisfy the query without needing to read from the primary table
    // (scan index), make that one slightly lower cost.
    boolean needsToReadFromScanIndex = true;
    if (!isScanIndex && allColumnsSet != null && !allColumnsSet.isEmpty()) {
        boolean foundAllColumnsWeNeed = true;
        for (Column c : allColumnsSet) {
            if (c.getTable() == getTable()) {
                boolean found = false;
                for (Column c2 : columns) {
                    if (c == c2) {
                        found = true;
                        break;
                    }
                }
                if (!found) {
                    foundAllColumnsWeNeed = false;
                    break;
                }
            }
        }
        if (foundAllColumnsWeNeed) {
            needsToReadFromScanIndex = false;
        }
    }
    long rc;
    if (isScanIndex) {
        rc = rowsCost + sortingCost + 20;
    } else if (needsToReadFromScanIndex) {
        rc = rowsCost + rowsCost + sortingCost + 20;
    } else {
        // The (20-x) calculation makes sure that when we pick a covering
        // index, we pick the covering index that has the smallest number of
        // columns (the more columns we have in index - the higher cost).
        // This is faster because a smaller index will fit into fewer data
        // blocks.
        rc = rowsCost + sortingCost + columns.length;
    }
    return rc;
}

Example 60 with Column

use of org.h2.table.Column in project h2database by h2database.

the class BaseIndex method initBaseIndex.

/**
 * Initialize the base index.
 *
 * @param newTable the table
 * @param id the object id
 * @param name the index name
 * @param newIndexColumns the columns that are indexed or null if this is
 *            not yet known
 * @param newIndexType the index type
 */
protected void initBaseIndex(Table newTable, int id, String name, IndexColumn[] newIndexColumns, IndexType newIndexType) {
    initSchemaObjectBase(newTable.getSchema(), id, name, Trace.INDEX);
    this.indexType = newIndexType;
    this.table = newTable;
    if (newIndexColumns != null) {
        this.indexColumns = newIndexColumns;
        columns = new Column[newIndexColumns.length];
        int len = columns.length;
        columnIds = new int[len];
        for (int i = 0; i < len; i++) {
            Column col = newIndexColumns[i].column;
            columns[i] = col;
            columnIds[i] = col.getColumnId();
        }
    }
}