/**
* @brief Generates the parallel query plan from a given SQL query
* @param query SQL query that will be parallelised
* @param headNodeTables list of tables that are completely located on the head node and are not sharded
* @return the raw sharded queries to be run on the coordination and shard nodes
*
* These function will create a parallel query plan from an input SQL statement
* using shard-query-parallel. It will identify any implicit joins, properly separate
* them into distinct queries and assign them to temporary tables. Further any aggregate
* function is properly transfered into sharded versions. This function will eventually
* produce a query plan that can be further processed by the query plan to SQL parser.
*/
function PHPSQLprepareQuery($query, $headNodeTables = array())
{
$shard_query = new ShardQuery();
$shard_query->verbose = false;
$shard_query->headNodeTables = $headNodeTables;
$shard_query->process_sql($query);
if (!empty($shard_query->errors)) {
echo "An Error occured:\n\n";
foreach ($shard_query->errors as $key => $error) {
if (array_key_exists("error_clause", $error)) {
echo $key . ": clause: " . $error["error_clause"] . " error: " . $error["error_reason"] . "\n";
} else {
echo $key . ": clause: " . $error[0] . " error: " . $error[1] . "\n";
}
}
throw new Exception('SQL Parse Error');
}
#determine if this is a serial or parallel query:
#parallel only if there are other tables than temporary (i.e. dependent) ones involved
$parallel = false;
if (!empty($shard_query->parsedCopy['FROM'])) {
foreach ($shard_query->parsedCopy['FROM'] as $fromNode) {
if ($fromNode['table'] != 'DEPENDENT-SUBQUERY') {
$parallel = true;
//check if this table is only available on the head node
//if yes, donot execute the query in parallel
$found = false;
$tableName = str_replace("`", "", $fromNode['table']);
$posDot = strpos($tableName, ".");
foreach ($headNodeTables as $headNodeTable) {
$posTable = strpos($tableName, $headNodeTable);
if ($posTable !== false) {
if ($posDot === false) {
if (strlen($tableName) === strlen($headNodeTable)) {
$found = true;
}
} else {
if (strlen($tableName) - $posDot - 1 === strlen($headNodeTable)) {
$found = true;
} else {
if ($posTable == 0 && strlen($headNodeTable) == $posDot) {
$found = true;
}
}
}
if ($found === true) {
$parallel = false;
break;
}
}
}
}
}
}
$shard_query->subqueries[$shard_query->table_name] = $shard_query->shard_sql;
$shard_query->subqueries[$shard_query->table_name]['parallel'] = $parallel;
return $shard_query;
}
function fetch()
{
$schema_id = $this->params['schema_id'];
$job_id = $this->params['job_id'];
//lookup schema name
$schema = Doo::db()->getOne('Schemata', array('where' => 'id = ' . $schema_id));
//update jobs before we check!
$shard_query = new ShardQuery($schema->schema_name);
$shard_query->state->mapper->sweep_jobs();
//get job
$j = new Jobs();
$j->id = $job_id;
$j = $j->getOne();
//check if job exist
if (!$j) {
$this->res->success = false;
$this->res->message = "Job_ID: {$job_id} doesnt exist!";
return null;
}
//check if job compeleted
if ($j->job_status != 'completed') {
$this->res->success = false;
$this->res->message = "Job_ID: {$job_id} not completed!";
} else {
//get result from job_id
$stmt = $shard_query->get_async_result($job_id);
//build data
if ($stmt) {
$this->res->success = true;
$this->res->data = $this->json_format($shard_query, $stmt);
$shard_query->DAL->my_free_result($stmt);
} else {
//error
$this->res->success = false;
$this->res->data = $stmt;
$this->res->message = $shard_query->DAL->my_error();
}
}
}
protected function process_sql($sql, &$state)
{
//only useful for the fetch worker for debugging
$state->sql = $sql;
$parser = null;
$straight_join = false;
$state->shard_sql = "";
//identical SQL which will be broadcast to all shards
$state->coord_sql = "";
//the summary table sql
$state->in_lists = array();
$error = array();
$select = null;
if (!is_array($sql)) {
#//we need to check the syntax
$sql = preg_replace(array("%-- [^\\n](?:\\n|\$)%", "%/\\*.*\\*/%"), '', trim($sql));
if (!$sql) {
$this->errors[] = "SQL is empty\n";
return false;
}
if (strtolower(substr($sql, 0, 4)) == 'with') {
// handle the WITH clauses and rewrite the SQL to use the new table names
$sql = $this->process_subquery_factoring($sql);
if (!$sql) {
return false;
}
}
if (strtolower(substr($sql, 0, 4)) == 'load') {
$result = $this->process_load_data($sql);
if (!$result) {
return false;
}
}
$blacklist = '/(?:create|drop|alter)\\s+database|last_insert_id|sql_calc_found_rows|row_count|:=|connection_id|' . 'current_user|session_user|user\\(\\)|mysql\\.|system_user|found_rows|get_lock|free_lock|' . 'is_free_lock|is_used_lock|load_file|infile|master_pos_wait|name_const|release_lock|^show\\s+(?:master|slave)|' . '^show\\s+bin|^show\\s+create\\s+database|^show\\s+databases|^show\\s+logs|^show\\s+mutex|' . '^show\\s+engine|^show\\s+innodb|^show\\s+open|^show\\s+privileges|^show\\s+(?:status|variables)|^lock\\s+table|' . '^check\\s+table|^checksum\\s+table|^backup|^repair|^restore|^call|^handler|^begin|^start\\s+transaction|^commit|' . '^rollback|^set transaction|savepoint|^xa\\s+(?:start|begin|end|prepare|commit|rollback|recover)/i';
if (preg_match($blacklist, $sql, $matches)) {
$this->errors[] = 'Unsupported SQL: ' . print_r($matches, true);
return false;
}
#syntax check is broken on ICE due to LIMIT 0 issue
$version_check_sql = 'select @@version_comment c';
$stmt = $state->DAL->my_query($version_check_sql);
$comment = "";
while ($row = $state->DAL->my_fetch_assoc($stmt)) {
$comment = $row['c'];
}
if (strpos($comment, '(ice)') === false) {
if (preg_match('/^select/i', $sql)) {
$check_sql = trim($sql, "; \n");
//custom functions have to pass the syntax check. concat takes a variable number of
//parameters, so it can be substituted for any custom function for syntax purposes
foreach (ShardQueryCustomFunctions::$list as $key => $val) {
$check_sql = preg_replace('/' . $key . '/i', 'concat', $check_sql);
}
//we need to remove the virtual schema name from any tables in the FROM clause
//The parser could be used here, but a simple regex will suffice for this simple
//syntax check
$schema_tokens = array('"' . $this->current_schema . '"' . ".", "`{$this->current_schema}`.", $this->current_schema . ".");
$check_sql = str_replace($schema_tokens, "", $check_sql);
$check_sql = preg_replace('/\\s+limit\\s+\\d+,*\\s*\\d*/i', '', $check_sql) . ' LIMIT 0';
$check_sql = "select count(*) from (" . trim($check_sql, ";\r\n ") . ") check_sql where 0=1";
/* if(!$state->DAL->my_query($check_sql)) {
$this->errors[] = $state->DAL->my_error();
return false;
}*/
}
}
$sql = preg_replace("/\\s+FROM\\s+(LAST|FIRST)\\s+/i", "FROM_\$1 ", $sql);
$state->parsed = $this->parser->parse($sql);
} else {
$state->parsed = $sql;
}
if (!empty($state->parsed['UNION ALL'])) {
$queries = array();
$table_name = "aggregation_tmp_" . mt_rand(1, 100000000);
$state->table_name = $table_name;
$coord_sql = "";
foreach ($state->parsed['UNION ALL'] as $sub_tree) {
$sub_state = ShardQuery::new_state();
//initialize the new state with a call to set_schema
$this->set_schema($this->schema_name, $sub_state);
$sub_state->tmp_shard = $state->tmp_shard;
$sub_table_name = "aggregation_tmp_" . mt_rand(1, 100000000);
$sub_state->table_name = $sub_table_name;
$sub_state->DAL = SimpleDAL::factory($sub_state->tmp_shard);
$this->query($sub_tree, false, $sub_state, true, false);
$state->extra_tables[] = $sub_table_name;
$state->extra_tables = array_merge($state->extra_tables, $sub_state->extra_tables);
if ($coord_sql) {
$coord_sql .= " UNION ALL ";
}
$coord_sql .= "( " . $sub_state->coord_sql . " )";
$state->extra_tables[] = $sub_table_name;
}
$select['coord_sql'] = $coord_sql;
unset($coord_sql);
} elseif (!empty($state->parsed['UNION'])) {
$queries = array();
$table_name = "aggregation_tmp_" . mt_rand(1, 100000000);
$state->table_name = $table_name;
$coord_sql = "";
foreach ($state->parsed['UNION'] as $sub_tree) {
$sub_state = shardquery::new_state();
//initialize the new state with a call to set_schema
$this->set_schema($this->schema_name, $sub_state);
$sub_state->tmp_shard = $state->tmp_shard;
$sub_table_name = "aggregation_tmp_" . mt_rand(1, 100000000);
$sub_state->table_name = $sub_table_name;
$sub_state->dal = simpledal::factory($sub_state->tmp_shard);
$this->query($sub_tree, false, $sub_state, true, false);
$state->extra_tables[] = $sub_table_name;
$state->extra_tables = array_merge($state->extra_tables, $sub_state->extra_tables);
if ($coord_sql) {
$coord_sql .= " UNION ";
}
$coord_sql .= "( " . $sub_state->coord_sql . " )";
}
//UNION operation requires deduplication of the temporary table
$select['coord_sql'] = $coord_sql;
unset($coord_sql);
} elseif (!empty($state->parsed['SELECT']) && empty($state->parsed['INSERT']) && empty($state->parsed['CREATE']) && empty($state->parsed['REPLACE'])) {
//reset the important variables
$select = $from = $where = $group = $order_by = "";
$straight_join = $distinct = false;
$this->errors = array();
/* Attempt star schema optimization */
if ($state->star_opt) {
$star_result = $this->star_optimize($state);
if ($star_result !== false) {
$state->parsed = $star_result['parsed'];
$state->push_where = $star_result['push_where'];
} else {
#critical error occured during star optimization
if (!empty($this->errors)) {
return false;
}
}
}
//The SELECT clause is processed first.
if (!empty($state->parsed['OPTIONS']) && in_array('STRAIGHT_JOIN', $state->parsed['OPTIONS'])) {
$straight_join = true;
}
if (strtoupper($state->parsed['SELECT'][0]['base_expr']) == 'DISTINCT') {
$distinct = true;
}
if (!empty($state->parsed['OPTIONS']) && in_array('SQL_CALC_FOUND_ROWS', $state->parsed['OPTIONS'])) {
$this->errors[] = array('Unsupported query', 'SQL_CALC_FOUND_ROWS is not supported');
return false;
}
if (!empty($state->parsed['OPTIONS']) && in_array('FOR UPDATE', $state->parsed['OPTIONS'])) {
$this->errors[] = array('Unsupported query', 'FOR UPDATE is not supported');
return false;
}
if (!empty($state->parsed['OPTIONS']) && in_array('LOCK IN SHARE MODE', $state->parsed['OPTIONS'])) {
$this->errors[] = array('Unsupported query', 'LOCK IN SHARE MODE is not supported');
return false;
}
$with_rollup = "";
if (!empty($state->parsed['OPTIONS'])) {
foreach ($state->parsed['OPTIONS'] as $option) {
if (strtoupper($option['base_expr']) === 'WITH ROLLUP') {
$with_rollup = ' WITH ROLLUP';
}
}
}
//ignore any other options
unset($state->parsed['OPTIONS']);
$procedure = "";
if (!empty($state->parsed['PROCEDURE'])) {
$procedure = 'PROCEDURE ' . join('', $state->parsed['PROCEDURE']);
unset($state->parsed['PROCEDURE']);
}
if (!empty($state->parsed['INTO'])) {
$this->errors[] = array('Unsupported query', 'INTO is not supported');
return false;
}
/*This will process the SELECT clause, doing any SQL rewrites needed for aggregation at the shard level
The $this->non_distrib flag will be set if the query contains any non-distributable aggregate functions (none currently)
If non-distributable aggregate functions are detected, we will throw this work away and instead use
$this->process_undistributable_select() [below]
*/
$select = $this->process_select($state->parsed['SELECT'], $straight_join, $distinct, $state);
/* Now some special window function columns are needed */
if (!empty($state->windows)) {
$used_cols = array();
for ($i = 0; $i < count($state->windows); ++$i) {
$win = $state->windows[$i];
$shard_hash = "";
foreach ($win['partition'] as $part) {
if (empty($used_cols[$part['base_expr']])) {
$select['shard_sql'] .= "," . $part['base_expr'];
$used_cols[$part['base_expr']] = 1;
} else {
continue;
}
if ($shard_hash) {
$shard_hash .= ",";
}
$shard_hash .= $part['base_expr'];
}
if ($shard_hash == "") {
$shard_hash = "'ONE_PARTITION'";
}
$select['shard_sql'] .= ",SHA1(CONCAT_WS('#'," . $shard_hash . ")) as wf{$i}_hash";
$obclause = "";
$obhash = "";
foreach ($win['order'] as $ob) {
if (empty($used_cols[$ob['base_expr']])) {
$select['shard_sql'] .= "," . $ob['base_expr'];
$used_cols[$ob['base_expr']] = 1;
}
if ($obclause) {
$obclause .= ",";
}
if ($obhash) {
$obclause .= ",";
}
$obclause .= $ob['base_expr'] . " " . $ob['direction'];
$obhash .= $ob['base_expr'];
}
if ($obhash) {
$select['shard_sql'] .= ",SHA1(CONCAT_WS('#'," . $obhash . ")) as wf{$i}_obhash";
}
$state->windows[$i]['order_by'] = $obclause;
}
}
if (trim($select['shard_sql']) == 'SELECT') {
$select['shard_sql'] = 'SELECT 1';
}
if (!empty($select['error'])) {
$this->errors[] = $select['error'];
return false;
}
if (!$state->non_distrib) {
unset($state->parsed['SELECT']);
} else {
$select = $this->process_undistributable_select($state->parsed['SELECT'], $straight_join, $distinct);
unset($state->parsed['SELECT']);
}
if (!empty($select['error'])) {
$this->errors[] = $select['error'];
return false;
}
$coord_group = "";
$shard_group = "";
if (!empty($state->parsed['GROUP'])) {
$group = $state->parsed['GROUP'];
foreach ($group as $item) {
if ($coord_group) {
$coord_group .= ",";
}
$coord_group .= $this->process_group_item($item, $state->used_colrefs, 0, $select);
}
}
if ($shard_group !== "") {
if ($select['group_aliases'] !== "") {
$select['group_aliases'] .= ",";
}
$select['group_aliases'] .= $shard_group;
}
$select['coord_group'] = $coord_group;
$select['shard_group'] = $select['group_aliases'];
if (empty($state->pushed) && empty($state->parsed['GROUP'])) {
$select['coord_group'] = "";
$select['shard_group'] = "";
}
unset($state->parsed['GROUP']);
if ($having_info = $this->process_having($state)) {
if (trim($having_info['select'])) {
$select['shard_sql'] .= "," . $having_info['select'];
}
} else {
$having_info = array('having' => " ");
}
$order_by = "";
if (!empty($state->windows)) {
$order_by = "wf0_hash";
if (!empty($state->windows[0]['order_by'])) {
$order_by .= ",";
$order_by .= $state->windows[0]['order_by'];
}
}
if (!empty($state->parsed['ORDER'])) {
foreach ($state->parsed['ORDER'] as $o) {
if ($order_by) {
$order_by .= ',';
}
switch ($o['expr_type']) {
case 'subquery':
$this->errors[] = "Subqueries are not supported in the ORDER BY clause.\n";
return false;
break;
case 'custom_function':
$this->errors[] = "Custom functions are not supported in the ORDER BY clause.\n";
return false;
break;
case 'function':
case 'expression':
case 'aggregate_function':
$item = "";
$expr_alias = 'expr_' . mt_rand(1, 10000000000);
$this->concat_all_subtrees($o, $item);
$select['shard_sql'] .= ", {$item} as {$expr_alias}";
$order_by .= $o['base_expr'] . '(' . $expr_alias . ')';
if ($o['expr_type'] === 'aggregate_function') {
switch (strtoupper($o['base_expr'])) {
case 'SUM':
$select['coord_odku'][] = "{$expr_alias}={$expr_alias} + VALUES({$expr_alias})";
break;
case 'MIN':
$select['coord_odku'][] = "{$expr_alias}=IF({$expr_alias} < VALUES({$expr_alias}), VALUES({$expr_alias}),{$expr_alias})";
break;
case 'MAX':
$select['coord_odku'][] = "{$expr_alias}=IF({$expr_alias} > VALUES({$expr_alias}), VALUES({$expr_alias}), {$expr_alias})";
break;
case 'COUNT':
$select['coord_odku'][] = "{$expr_alias}={$expr_alias} + VALUES({$expr_alias})";
break;
default:
$this->errors[] = "Unsupported aggregate function in ORDER BY";
return false;
}
}
break;
default:
if (strpos($o['base_expr'], '.') !== false) {
$expr_alias = 'expr_' . mt_rand(1, 10000000000);
$select['shard_sql'] .= ", {$o['base_expr']} as {$expr_alias}";
$order_by .= $expr_alias;
} else {
$order_by .= $o['base_expr'];
}
break;
}
$order_by .= " " . $o['direction'];
}
}
if ($order_by) {
$order_by = " ORDER BY {$order_by}";
}
unset($state->parsed['ORDER']);
if (empty($state->parsed['FROM'])) {
$this->errors = array('Unsupported query', 'Missing FROM clause');
return false;
} else {
$select['shard_sql'] .= "\n" . $this->process_from($state->parsed['FROM'], $state);
$in_tables = "";
$is_virtual = false;
foreach ($state->tables as $val => $attr) {
if ($attr['is_virtual']) {
$is_virtual = true;
}
if ($in_tables !== "") {
$in_tables .= ",";
}
$in_tables .= "'{$val}'";
}
/*
* If no real tables were used (only subquery in from clause for example)
* then direct the query to the coordinator shard, as it will read from
* the output of the subquery in the from clause or other construct.
*/
if ($in_tables === "") {
$state->force_shard = array($state->tmp_shard);
} elseif ($in_tables !== "" && !$is_virtual) {
/*
* Otherwise, if this isn't a virtual table (v_ view) then we have to inspect
* the tables to see if any of them contain the shard key. If any v_ tables are
* used then we assume it is sharded (what is point of virtual table otherwise?)
*/
$sql = "select count(*) cnt from information_schema.columns where table_schema='" . $state->tmp_shard['db'] . "' and column_name='" . $this->shard_column . "' and table_name IN({$in_tables});";
if (!($stmt = $state->DAL->my_query($sql))) {
$this->errors[] = 'Could not access information schema: ' . $state->DAL->my_error();
return false;
}
$row = $state->DAL->my_fetch_assoc();
/* If none of the tables contain the sharding key, the query goes to all shards */
if ($row['cnt'] === '0') {
if (isset($state->tmp_shard)) {
$state->force_shard = array($state->tmp_shard);
} else {
$state->force_shard = array($state->shards[array_rand($state->shards)]);
}
}
} else {
$state->force_shard = array();
}
if (!isset($state->table_name) || $state->table_name == "") {
$state->table_name = "aggregation_tmp_" . mt_rand(1, 100000000);
}
$select['coord_sql'] .= "\nFROM `{$state->table_name}`";
$select['winfunc_sql'] .= "\nFROM `{$state->table_name}`";
unset($state->parsed['FROM']);
}
//note that this will extract inlists and store them in $this->in_lists (if inlist optimization is on)
$where_clauses = $this->process_where(empty($state->parsed['WHERE']) ? array() : $state->parsed['WHERE'], $state);
if (!empty($state->parsed['WHERE'])) {
unset($state->parsed['WHERE']);
}
if (empty($state->force_shard)) {
$state->force_shard = $state->shards;
}
/* Handle dependent subqueries if the subquery has to be on one or more shards that are different from tmp_shard.*/
foreach ($state->dependent_subqueries as $sub_table) {
if (empty($state->tables)) {
continue;
}
//don't do this work if there are no real tables
$sql = "SHOW CREATE TABLE {$sub_table}";
$stmt = $state->DAL->my_query($sql);
$row = $state->DAL->my_fetch_array();
$create_sql = $row[1];
if (!$row) {
$this->errors[] = 'Could not get DDL for intermediate table: ' . $sub_table . "(" . $state->DAL->my_error() . ")";
$this->cleanup_tables($state);
return false;
}
$export_sql = "SELECT * FROM {$sub_table}";
$stmt = $state->DAL->my_unbuffered_query($export_sql);
if (!$stmt) {
$this->errors[] = 'Could not open intermediate result from: ' . $sub_table . "(" . $state->DAL->my_error() . ")";
$this->cleanup_tables($state);
return false;
}
$fname = tempnam('/tmp', 'SQ');
$fh = fopen($fname, 'wb');
if (!$fh) {
$this->errors[] = 'Could not open temporary file for spooling dependent subquery to shards: ' . $fname;
return false;
}
while ($row = $state->DAL->my_fetch_array()) {
$outrow = "";
foreach ($row as $col) {
$col = str_replace('"', '\\"', $col);
if (!is_numeric($col)) {
$col = '"' . $col . '"';
}
if ($outrow) {
$outrow .= ",";
}
$outrow .= $col;
}
if (!fputs($fh, $outrow . "\n")) {
$this->errors[] = 'Could not write to temporary file for spooling dependent subquery to shards: ' . $fname;
return false;
}
}
fclose($fh);
foreach ($state->force_shard as $shard) {
if ($shard === $state->tmp_shard) {
continue;
}
$dal = SimpleDAL::factory($shard);
$dal->my_select_db($shard['db']);
$stmt = $dal->my_query($create_sql);
if (!$stmt) {
$this->errors[] = "Failed to create destination table: {$sub_table} during intermediate copy" . "(" . $dal->my_error() . ")";
$this->cleanup_tables($state);
return false;
}
$load_sql = "LOAD DATA LOCAL INFILE '{$fname}' INTO TABLE `{$shard['db']}`.{$sub_table} FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '\"' ESCAPED BY '\\\\'";
$stmt = $dal->my_query($load_sql);
if (!$stmt) {
$this->errors[] = 'Failed to LOAD DATA LOCAL INFILE to table: $sub_table during intermediate copy' . "(" . $dal->my_error() . ")";
$this->cleanup_tables($state);
return false;
}
$dal->my_close();
}
unlink($fname);
}
/* semijoin optimization */
if (!empty($state->push_join)) {
$select['shard_sql'] .= join('', $state->push_join);
}
$used_limit = 0;
if (!empty($state->parsed['LIMIT'])) {
$used_limit = 1;
if ($state->parsed['LIMIT']['offset'] == "") {
$state->parsed['LIMIT']['offset'] = 0;
}
$order_by .= " LIMIT {$state->parsed['LIMIT']['offset']},{$state->parsed['LIMIT']['rowcount']}";
unset($state->parsed['LIMIT']);
}
foreach ($state->parsed as $key => $clauses) {
$this->errors[] = array('Unsupported query', $key . ' clause is not supported');
}
if ($this->errors) {
return false;
}
//process_select only provides a list of positions
if ($select['coord_group']) {
$select['coord_group'] = ' GROUP BY ' . $select['coord_group'] . $having_info['having'] . $with_rollup . $procedure;
}
if ($select['shard_group']) {
$select['shard_group'] = ' GROUP BY ' . $select['shard_group'];
}
$queries = array();
$where_base = " 1=1 ";
if (!empty($state->push_where)) {
$where_base .= ' AND ' . join(' ', $state->push_where);
}
if ($state->mysql_version['supports_partition_hint'] == 1) {
#if table is not partitioned, then don't inject any partition hints
#have to do all removals in a first pass
foreach ($state->tables as $table_name => $table_info) {
if (empty($table_info['alias']) || $table_info['alias'] === '') {
$alias = $table_name;
} else {
$alias = $table_info['alias'];
}
$alias = trim($alias, '`');
if ($table_info['partition_info']['partition_names'][0] == "") {
$select['shard_sql'] = str_replace('%p' . $alias, "", $select['shard_sql']);
}
}
#now build out queries for each partition for each table
foreach ($state->tables as $table_name => $table_info) {
if (empty($table_info['alias']) || $table_info['alias'] === '') {
$alias = $table_name;
} else {
$alias = $table_info['alias'];
}
$alias = trim($alias, '`');
if ($table_info['partition_info']['partition_names'][0] != "") {
if (empty($queries)) {
foreach ($table_info['partition_info']['partition_names'] as $x => $partition_name) {
$queries[] = str_replace('%p' . $alias, " PARTITION(" . $partition_name . ") ", $select['shard_sql']);
}
} else {
$old_queries = $queries;
$queries = array();
foreach ($old_queries as $query) {
foreach ($table_info['partition_info']['partition_names'] as $x => $partition_name) {
$query = str_replace('%p' . $alias, " PARTITION(" . $partition_name . ") ", $query);
$queries[] = $query;
}
}
}
#remove the token so that it doesn't mess up further tables in the query
$select['shard_sql'] = str_replace('%p' . $alias, "", $select['shard_sql']);
}
}
} else {
$explain_query = "EXPLAIN PARTITIONS " . $select['shard_sql'] . ' ' . $where;
$stmt = $state->DAL->my_query($explain_query);
$state->added_where = 0;
if ($where == "") {
$where = " WHERE 1=1";
}
while ($row = $state->DAL->my_fetch_assoc($stmt)) {
$table_or_alias = $row['table'];
$partitions = $row['partitions'];
$partitions = explode(',', $partitions);
foreach ($partitions as $partition_name) {
foreach ($state->tables as $table_name => $table_info) {
if ($table_or_alias === $table_name || $table_or_alias === $table_info['alias']) {
if (!empty($table_info['partition_info']['where_clauses'][$partition_name])) {
$expr = $table_info['partition_info']['where_clauses'][$partition_name];
if ($table_info['alias'] !== '') {
$expr = preg_replace("/" . $table_info['partition_info']['partition_expression'] . "/", $table_info['alias'] . '.' . $table_info['partition_info']['partition_expression'], $expr);
}
$queries[] = $select['shard_sql'] . ' ' . $where . ' AND ' . $expr;
$state->added_where = 1;
}
}
}
}
}
}
$where_base = $state->added_where != 1 ? " WHERE {$where_base} " : " AND 1=1 ";
if (empty($where_clauses)) {
$where_clauses = array($where_base);
} else {
$old_clauses = $where_clauses;
$where_clauses = array();
foreach ($old_clauses as $new_where_clause) {
$where_clauses[] = $where_base . ' AND ' . $new_where_clause;
}
}
#queries is empty if no partition parallelism was added
#parallelism may still have been added from BETWEEN clauses ($where_clauses may be an array of clauses)
if (empty($queries)) {
foreach ($where_clauses as $where_clause) {
if (!$state->no_pushdown_limit) {
$queries[] = $select['shard_sql'] . $where_clause . $select['shard_group'] . ($used_limit ? $order_by : '');
} else {
$queries[] = $select['shard_sql'] . $where_clause . $select['shard_group'];
}
}
} else {
$old_queries = $queries;
$queries = array();
foreach ($old_queries as $query) {
foreach ($where_clauses as $where_clause) {
if (!$state->no_pushdown_limit) {
$nq = $query . ' ' . $where_clause . ' ' . $select['shard_group'] . ($used_limit ? $order_by : '');
} else {
$nq = $query . ' ' . $where_clause . ' ' . $select['shard_group'];
}
$queries[] = $nq;
}
}
}
} elseif (!empty($state->parsed['INSERT']) || !empty($state->parsed['REPLACE'])) {
if (!empty($state->parsed['INSERT'])) {
$replace = "";
$to_table = $state->parsed['INSERT'][1]['table'];
} else {
$replace = " REPLACE ";
$to_table = $state->parsed['REPLACE'][1]['table'];
}
$result = $this->get_insert_cols($state);
if ($result === false) {
return false;
}
$cols = $result[0];
$col_list = $result[1];
$shard_column_pos = false;
foreach ($cols as $pos => $col) {
if (trim($col, '` ') == $this->shard_column) {
$shard_column_pos = $pos;
break;
}
}
if (!empty($state->parsed['SELECT'])) {
$parsed = $state->parsed;
$ignore = "";
if (!empty($parsed['OPTIONS'])) {
foreach ($parsed['OPTIONS'] as $option) {
if (strtolower($option) == 'ignore') {
$ignore = 'ignore';
break;
}
}
}
unset($parsed['INSERT']);
unset($parsed['REPLACE']);
unset($parsed['OPTIONS']);
$sub_state = shardquery::new_state();
$this->set_schema($this->schema_name, $sub_state);
$sub_state->tmp_shard = $state->tmp_shard;
$sub_table_name = "aggregation_tmp_" . mt_rand(1, 100000000);
$sub_state->table_name = $sub_table_name;
$sub_state->dal = simpledal::factory($sub_state->tmp_shard);
$this->query($parsed, false, $sub_state, true, false);
$state->extra_tables[] = $sub_table_name;
$state->extra_tables = array_merge($state->extra_tables, $sub_state->extra_tables);
$result = $this->load_from_table($sub_state, $to_table, $col_list, $shard_column_pos, $ignore, $replace);
if ($result) {
$this->state->coord_sql = "select 'INSERT .. SELECT completed ok' as message from dual";
return true;
} else {
return false;
}
} else {
if ($replace == "") {
$sql = "INSERT INTO `" . trim($state->parsed['INSERT'][1]['table'], '`') . "` {$col_list} VALUES ";
$replace = "INSERT";
} else {
$sql = "REPLACE INTO `" . trim($state->parsed['REPLACE'][1]['table'], '`') . "` {$col_list} VALUES ";
}
$values = array();
$val_count = 0;
$column_count = count($cols);
foreach ($state->parsed['VALUES'] as $record) {
$vals = trim($record['base_expr'], ',');
//this row is going to go to a single shard
if ($shard_column_pos !== false) {
if (count($record['data']) !== $column_count) {
$this->errors[] = 'Value count does not match column count!';
return false;
}
$shard_id = $this->map_shard($this->shard_column, $record['data'][$shard_column_pos]['base_expr'], $this->state->schema_name, '=', true);
$shard_id = @array_pop(array_keys(array_pop($shard_id)));
if (empty($values[$shard_id])) {
$values[$shard_id] = $vals;
} else {
$values[$shard_id] .= ",{$vals}";
}
$val_count++;
//the row is going to all shards
} else {
foreach ($this->shards as $shard_id => $shard) {
if (empty($values[$shard_id])) {
$values[$shard_id] = $vals;
} else {
$values[$shard_id] .= ",{$vals}";
}
$val_count++;
}
}
}
$state->insert_sql = $sql;
$state->insert_values = $values;
}
return true;
} else {
if (!empty($state->parsed['CREATE']) && !empty($state->parsed['TABLE']) && !empty($state->parsed['SELECT'])) {
/* CTAS */
$table_name = $state->parsed['TABLE']['base_expr'];
$schema_tokens = array(';', '"' . $this->current_schema . '"' . ".", "`{$this->current_schema}`.", $this->current_schema . ".");
$create_sql = $state->orig_sql;
$create_sql = str_replace($schema_tokens, "", $create_sql);
$create_sql = preg_replace('/\\s+limit\\s+\\d+/i', '', $create_sql) . ' LIMIT 0';
foreach ($this->shards as $name => $shard) {
$dal = SimpleDAL::factory($shard);
$dal->my_select_db($shard['db']);
$dal->my_query($create_sql);
if ($dal->my_error()) {
$this->errors[] = "on shard: " . $name . " errorno:" . $dal->my_errno() . ",message:" . $dal->my_error();
}
$dal->my_close();
}
unset($state->parsed['CREATE']);
unset($state->parsed['TABLE']);
$result = $this->get_insert_cols($state, $table_name);
if ($result === false) {
return false;
}
$cols = $result[0];
$col_list = $result[1];
$shard_column_pos = false;
foreach ($cols as $pos => $col) {
if (trim($col, '` ') == $this->shard_column) {
$shard_column_pos = $pos;
break;
}
}
$ignore = "";
$replace = "";
$sub_state = shardquery::new_state();
$this->set_schema($this->schema_name, $sub_state);
$sub_state->tmp_shard = $state->tmp_shard;
$sub_table_name = "aggregation_tmp_" . mt_rand(1, 100000000);
$sub_state->table_name = $sub_table_name;
$sub_state->dal = simpledal::factory($sub_state->tmp_shard);
$this->query($state->parsed, false, $sub_state, true, false);
$state->extra_tables[] = $sub_table_name;
$state->extra_tables = array_merge($state->extra_tables, $sub_state->extra_tables);
$result = $this->load_from_table($sub_state, $table_name, "", $shard_column_pos, $ignore, $replace);
if ($result) {
$this->state->coord_sql = "select 'CREATE .. SELECT completed ok' as message from dual";
return true;
} else {
return false;
}
}
/*else*/
//This query should be broadcast to all nodes
#$state->broadcast_query = $state->orig_sql;
foreach ($this->shards as $shard_name => $shard) {
$dal = SimpleDAL::factory($shard);
$dal->my_select_db($shard['db']);
if ($dal->my_error()) {
$this->errors[] = $dal->my_error();
continue;
}
$dal->my_query($state->orig_sql);
if ($dal->my_error()) {
$this->errors[] = $dal->my_error();
}
}
$this->state->coord_sql = "select 'Sent query to all shards' as message from dual";
return true;
}
//if(!isset($state->table_name)) $state->table_name = "agg_
if (empty($order_by)) {
$order_by = "";
}
if (empty($select['coord_group'])) {
$select['coord_group'] = "";
}
if (empty($select['coord_odku'])) {
$select['coord_odku'] = "";
}
if (empty($select['group_aliases'])) {
$select['group_aliases'] = "";
}
$state->coord_sql = $select['coord_sql'] . ' ' . $select['coord_group'] . ' ' . $order_by;
$state->winfunc_sql = $select['winfunc_sql'];
$state->winfunc_group = $select['coord_group'];
if (!isset($state->coord_odku) || empty($state->coord_odku)) {
$state->coord_odku = $select['coord_odku'];
}
$state->shard_sql = $queries;
$state->agg_key_cols = $select['group_aliases'];
if (!empty($select['custom_functions'])) {
$state->custom_functions = $select['custom_functions'];
} else {
$state->custom_functions = array();
}
$explain = "Shard-Query optimizer messages:";
if ($state->agg_key_cols) {
$explain .= "\n * The following projections may be selected for a UNIQUE CHECK on the storage node operation:\n {$state->agg_key_cols}\n";
if ($state->coord_odku) {
$explain .= "\n * storage node result set merge optimization enabled:\n ON DUPLICATE KEY UPDATE\n\t" . join(",\n\t", $state->coord_odku);
}
}
if (isset($state->messages)) {
foreach ($state->messages as $msg) {
$explain .= "\n * {$msg}";
}
}
if ($state->non_distrib) {
$explain .= "\n * Aggregation pushdown disabled due to use of non-distributable and/or custom functions.";
}
$explain .= "\n\nSQL TO SEND TO SHARDS:\n";
$explain .= print_r($state->shard_sql, true);
$explain .= "SQL TO SEND TO COORDINATOR NODE:\n{$state->coord_sql}\n";
$state->explain = $explain;
return true;
}
public function run($arg)
{
require 'shard-query-config.php';
if (isset($cache_servers) && !empty($cache_servers)) {
$this->cache = new SaltedCache($cache_servers);
}
if (isset($cache_rules) && !empty($cache_rules)) {
$this->cache_rules = $cache_rules;
}
if (!$arg) {
return false;
}
$arg = (object) $arg;
$fields = false;
$errors = false;
$rows = false;
$sql = "";
$has_rows = false;
$resultset = null;
if (!isset($arg->schema_name)) {
$arg->schema_name = null;
}
$SQ = new ShardQuery($arg->schema_name);
print_r($arg);
if (empty($arg->sql) || !trim($arg->sql)) {
return false;
}
if (stripos($arg->sql, 'select database()') !== false) {
$fields = array(array('type' => 250, 'name' => 'DATABASE()'));
$rows = array(array($SQ->state->schema_name));
$resultset = array('fields' => &$fields, 'rows' => &$rows);
} elseif (preg_match('/^SHOW/i', $arg->sql)) {
$shard_id = array_rand($SQ->state->shards);
$DAL = SimpleDAL::factory($SQ->state->shards[$shard_id]);
$DAL->my_select_db($SQ->state->shards[$shard_id]['db']);
if (preg_match('/show\\s+databases/i', $arg->sql)) {
$databases = $SQ->state->mapper->get_schemata();
$fields = array(array('type' => 250, 'name' => 'Database'));
/* $rows = array();
foreach($databases as $schema_info) {
$rows[] = array($schema_info['schema_name']);
}
*/
$rows = array(array($SQ->state->schema_name));
$resultset = array('fields' => &$fields, 'rows' => &$rows);
} elseif ($stmt = $DAL->my_query($arg->sql)) {
$row = $DAL->my_fetch_assoc();
foreach ($row as $field => $val) {
$rows[0][] = $val;
$fields[] = array('type' => 250, 'name' => $field);
}
while ($row = $DAL->my_fetch_array($stmt, MYSQL_NUM)) {
$rows[] = $row;
}
print_r($rows);
$resultset = array('fields' => &$fields, 'rows' => &$rows);
}
$DAL->my_close();
unset($DAL);
} elseif (preg_match('/select\\s+.*\\sfrom\\s.*/i', $arg->sql) || preg_match('/(create|drop|alter)\\s+.*/i', $arg->sql)) {
$cache_ttl = null;
if (isset($this->cache)) {
$patterns = $this->cache_rules;
foreach ($patterns as $pattern => $ttl) {
if (preg_match($pattern, $arg->sql)) {
$cache_ttl = $ttl;
$resultset = $this->cache->get($arg->sql, $arg->schema_name);
break;
}
}
}
if (!$resultset) {
$stmt = $SQ->query($arg->sql);
if (!empty($SQ->errors)) {
$errors = trim(str_replace(array("\n", "Array", "(", ")", " "), "", print_r($SQ->errors, true)));
}
if ($stmt) {
$has_rows = true;
$rows = array(array());
# get the first row and use it to construct the list of fields + collect row data
# in this first fetch we process data one output column at a time
$row = $SQ->DAL->my_fetch_assoc($stmt);
foreach ($row as $field => $val) {
$rows[0][] = $val;
$fields[] = array('type' => 250, 'name' => $field);
}
# fetch the rest of the rows numerically and stuff into $rows, a row at a time
while ($row = $SQ->DAL->my_fetch_array($stmt, MYSQL_NUM)) {
$rows[] = $row;
}
$resultset = array('fields' => &$fields, 'rows' => &$rows);
}
if (isset($cache_ttl)) {
$this->cache->set($arg->sql, $resultset, $cache_ttl, $arg->schema_name);
}
# return the actual object so that the proxy can finish aggregation and drop the table
}
} else {
$sql = $arg->sql;
}
return json_encode(array('resultset' => $resultset, 'errors' => $errors, 'sql' => $sql, 'has_rows' => $has_rows));
}
