Examples with Explain org.h2.command.dml.Explain used on opensource projects

Example 1 with Explain

use of org.h2.command.dml.Explain in project ignite by apache.

the class GridSqlQuerySplitter method split.

/**
     * @param stmt Prepared statement.
     * @param params Parameters.
     * @param collocatedGrpBy Whether the query has collocated GROUP BY keys.
     * @param distributedJoins If distributed joins enabled.
     * @param enforceJoinOrder Enforce join order.
     * @param h2 Indexing.
     * @return Two step query.
     * @throws SQLException If failed.
     * @throws IgniteCheckedException If failed.
     */
public static GridCacheTwoStepQuery split(JdbcPreparedStatement stmt, Object[] params, boolean collocatedGrpBy, boolean distributedJoins, boolean enforceJoinOrder, IgniteH2Indexing h2) throws SQLException, IgniteCheckedException {
    if (params == null)
        params = GridCacheSqlQuery.EMPTY_PARAMS;
    // Here we will just do initial query parsing. Do not use optimized
    // subqueries because we do not have unique FROM aliases yet.
    GridSqlQuery qry = parse(prepared(stmt), false);
    String originalSql = qry.getSQL();
    final boolean explain = qry.explain();
    qry.explain(false);
    GridSqlQuerySplitter splitter = new GridSqlQuerySplitter(params, collocatedGrpBy, h2.kernalContext());
    // Normalization will generate unique aliases for all the table filters in FROM.
    // Also it will collect all tables and schemas from the query.
    splitter.normalizeQuery(qry);
    Connection conn = stmt.getConnection();
    // Here we will have correct normalized AST with optimized join order.
    // The distributedJoins parameter is ignored because it is not relevant for
    // the REDUCE query optimization.
    qry = parse(optimize(h2, conn, qry.getSQL(), params, false, enforceJoinOrder), true);
    // Do the actual query split. We will update the original query AST, need to be careful.
    splitter.splitQuery(qry);
    // We must have at least one map query.
    assert !F.isEmpty(splitter.mapSqlQrys) : "map";
    // We must have a reduce query.
    assert splitter.rdcSqlQry != null : "rdc";
    // distributed joins at all.
    if (distributedJoins) {
        boolean allCollocated = true;
        for (GridCacheSqlQuery mapSqlQry : splitter.mapSqlQrys) {
            Prepared prepared = optimize(h2, conn, mapSqlQry.query(), mapSqlQry.parameters(params), true, enforceJoinOrder);
            allCollocated &= isCollocated((Query) prepared);
            mapSqlQry.query(parse(prepared, true).getSQL());
        }
        // We do not need distributed joins if all MAP queries are collocated.
        if (allCollocated)
            distributedJoins = false;
    }
    // Setup resulting two step query and return it.
    GridCacheTwoStepQuery twoStepQry = new GridCacheTwoStepQuery(originalSql, splitter.tbls);
    twoStepQry.reduceQuery(splitter.rdcSqlQry);
    for (GridCacheSqlQuery mapSqlQry : splitter.mapSqlQrys) twoStepQry.addMapQuery(mapSqlQry);
    twoStepQry.skipMergeTable(splitter.rdcQrySimple);
    twoStepQry.explain(explain);
    twoStepQry.distributedJoins(distributedJoins);
    // all map queries must have non-empty derivedPartitions to use this feature.
    twoStepQry.derivedPartitions(mergePartitionsFromMultipleQueries(twoStepQry.mapQueries()));
    return twoStepQry;
}

Example 2 with Explain

use of org.h2.command.dml.Explain in project ignite by apache.

the class GridSqlInsert method getSQL.

/**
 * {@inheritDoc}
 */
@Override
public String getSQL() {
    StatementBuilder buff = new StatementBuilder(explain() ? "EXPLAIN " : "");
    buff.append("INSERT").append("\nINTO ").append(into.getSQL()).append('(');
    for (GridSqlColumn col : cols) {
        buff.appendExceptFirst(", ");
        buff.append('\n').append(col.getSQL());
    }
    buff.append("\n)\n");
    if (direct)
        buff.append("DIRECT ");
    if (sorted)
        buff.append("SORTED ");
    if (!rows.isEmpty()) {
        buff.append("VALUES\n");
        StatementBuilder valuesBuff = new StatementBuilder();
        for (GridSqlElement[] row : rows()) {
            valuesBuff.appendExceptFirst(",\n");
            StatementBuilder rowBuff = new StatementBuilder("(");
            for (GridSqlElement e : row) {
                rowBuff.appendExceptFirst(", ");
                rowBuff.append(e != null ? e.getSQL() : "DEFAULT");
            }
            rowBuff.append(')');
            valuesBuff.append(rowBuff.toString());
        }
        buff.append(valuesBuff.toString());
    } else
        buff.append('\n').append(qry.getSQL());
    return buff.toString();
}

Example 3 with Explain

use of org.h2.command.dml.Explain in project ignite by apache.

the class GridSqlMerge method getSQL.

/**
 * {@inheritDoc}
 */
@Override
public String getSQL() {
    StatementBuilder buff = new StatementBuilder(explain() ? "EXPLAIN " : "");
    buff.append("MERGE INTO ").append(into.getSQL()).append("(");
    for (GridSqlColumn col : cols) {
        buff.appendExceptFirst(", ");
        buff.append('\n').append(col.getSQL());
    }
    buff.append("\n)\n");
    if (keys != null) {
        buff.append("KEY(\n");
        buff.resetCount();
        for (GridSqlColumn c : keys) {
            buff.appendExceptFirst(",\n");
            buff.append(c.getSQL());
        }
        buff.append(")\n");
    }
    if (!rows.isEmpty()) {
        buff.append("VALUES\n");
        StatementBuilder valuesBuff = new StatementBuilder();
        for (GridSqlElement[] row : rows()) {
            valuesBuff.appendExceptFirst(",\n");
            StatementBuilder rowBuff = new StatementBuilder("(");
            for (GridSqlElement e : row) {
                rowBuff.appendExceptFirst(", ");
                rowBuff.append(e != null ? e.getSQL() : "DEFAULT");
            }
            rowBuff.append(')');
            valuesBuff.append(rowBuff.toString());
        }
        buff.append(valuesBuff.toString());
    } else
        buff.append('\n').append(qry.getSQL());
    return buff.toString();
}

Example 4 with Explain

use of org.h2.command.dml.Explain in project ignite by apache.

the class IgniteH2Indexing method querySqlFields.

/**
 * {@inheritDoc}
 */
@SuppressWarnings({ "StringEquality", "unchecked" })
@Override
public List<FieldsQueryCursor<List<?>>> querySqlFields(String schemaName, SqlFieldsQuery qry, @Nullable SqlClientContext cliCtx, boolean keepBinary, boolean failOnMultipleStmts, GridQueryCancel cancel) {
    List<FieldsQueryCursor<List<?>>> res = tryQueryDistributedSqlFieldsNative(schemaName, qry.getSql(), cliCtx);
    if (res != null)
        return res;
    {
        // First, let's check if we already have a two-step query for this statement...
        H2TwoStepCachedQueryKey cachedQryKey = new H2TwoStepCachedQueryKey(schemaName, qry.getSql(), qry.isCollocated(), qry.isDistributedJoins(), qry.isEnforceJoinOrder(), qry.isLocal());
        H2TwoStepCachedQuery cachedQry;
        if ((cachedQry = twoStepCache.get(cachedQryKey)) != null) {
            checkQueryType(qry, true);
            GridCacheTwoStepQuery twoStepQry = cachedQry.query().copy();
            List<GridQueryFieldMetadata> meta = cachedQry.meta();
            res = Collections.singletonList(doRunDistributedQuery(schemaName, qry, twoStepQry, meta, keepBinary, cancel));
            if (!twoStepQry.explain())
                twoStepCache.putIfAbsent(cachedQryKey, new H2TwoStepCachedQuery(meta, twoStepQry.copy()));
            return res;
        }
    }
    {
        // Second, let's check if we already have a parsed statement...
        PreparedStatement cachedStmt;
        if ((cachedStmt = cachedStatement(connectionForSchema(schemaName), qry.getSql())) != null) {
            Prepared prepared = GridSqlQueryParser.prepared(cachedStmt);
            // We may use this cached statement only for local queries and non queries.
            if (qry.isLocal() || !prepared.isQuery())
                return (List<FieldsQueryCursor<List<?>>>) doRunPrepared(schemaName, prepared, qry, null, null, keepBinary, cancel);
        }
    }
    res = new ArrayList<>(1);
    int firstArg = 0;
    String remainingSql = qry.getSql();
    while (remainingSql != null) {
        ParsingResult parseRes = parseAndSplit(schemaName, remainingSql != qry.getSql() ? cloneFieldsQuery(qry).setSql(remainingSql) : qry, firstArg);
        // Let's avoid second reflection getter call by returning Prepared object too
        Prepared prepared = parseRes.prepared();
        GridCacheTwoStepQuery twoStepQry = parseRes.twoStepQuery();
        List<GridQueryFieldMetadata> meta = parseRes.meta();
        SqlFieldsQuery newQry = parseRes.newQuery();
        remainingSql = parseRes.remainingSql();
        if (remainingSql != null && failOnMultipleStmts)
            throw new IgniteSQLException("Multiple statements queries are not supported");
        firstArg += prepared.getParameters().size();
        res.addAll(doRunPrepared(schemaName, prepared, newQry, twoStepQry, meta, keepBinary, cancel));
        if (parseRes.twoStepQuery() != null && parseRes.twoStepQueryKey() != null && !parseRes.twoStepQuery().explain())
            twoStepCache.putIfAbsent(parseRes.twoStepQueryKey(), new H2TwoStepCachedQuery(meta, twoStepQry.copy()));
    }
    return res;
}

Example 5 with Explain

use of org.h2.command.dml.Explain in project ignite by apache.

the class GridSqlUnion method getSQL.

/**
 * {@inheritDoc}
 */
@Override
public String getSQL() {
    StatementBuilder buff = new StatementBuilder(explain() ? "EXPLAIN \n" : "");
    buff.append('(').append(left.getSQL()).append(')');
    switch(unionType()) {
        case SelectUnion.UNION_ALL:
            buff.append("\nUNION ALL\n");
            break;
        case SelectUnion.UNION:
            buff.append("\nUNION\n");
            break;
        case SelectUnion.INTERSECT:
            buff.append("\nINTERSECT\n");
            break;
        case SelectUnion.EXCEPT:
            buff.append("\nEXCEPT\n");
            break;
        default:
            throw new CacheException("type=" + unionType);
    }
    buff.append('(').append(right.getSQL()).append(')');
    getSortLimitSQL(buff);
    return buff.toString();
}