1
我使用N1QL從我的couchbase數據庫讀取數據,並遇到非常糟糕的表現。我正在處理atm的觀點,但如果有人知道爲什麼發生這種情況,我很高興知道,也許我會回到N1QL。儘管2M記錄(但有效)的分頁速度很慢,但分頁搜索超過了2M記錄。 Couchbase CE 4.1.0不良的N1QL性能
下面是該查詢:
public static function findByPage($recordsPerPage, $page) {
$query = CouchbaseN1qlQuery::fromString('SELECT * FROM `public_portal` WHERE `collection`=$collection ORDER BY `_id` LIMIT $limit OFFSET $offset');
$query->options['$collection'] = static::COLLECTION_NAME;
$query->options['$limit'] = $recordsPerPage;
$query->options['$offset'] = $recordsPerPage*($page-1);
return self::doQueryAndGetObjects($query);
}
的指標:
CREATE INDEX `public_portal_collection` ON `public_portal`(`collection`) USING GSI;
CREATE INDEX `public_portal_id` ON `public_portal`(`_id`) USING GSI;
我解釋:
cbq> EXPLAIN SELECT * FROM `public_portal` WHERE `collection`="tree" ORDER BY `_id` LIMIT 24 OFFSET 24;
{
"requestID": "ab6df326-8f33-48b6-84a4-c22ac394f803",
"signature": "json",
"results": [
{
"#operator": "Sequence",
"~children": [
{
"#operator": "Sequence",
"~children": [
{
"#operator": "IndexScan",
"index": "public_portal_collection",
"keyspace": "public_portal",
"namespace": "default",
"spans": [
{
"Range": {
"High": [
"\"tree\""
],
"Inclusion": 3,
"Low": [
"\"tree\""
]
}
}
],
"using": "gsi"
},
{
"#operator": "Parallel",
"~child": {
"#operator": "Sequence",
"~children": [
{
"#operator": "Fetch",
"keyspace": "public_portal",
"namespace": "default"
},
{
"#operator": "Filter",
"condition": "((`public_portal`.`collection`) = \"tree\")"
},
{
"#operator": "InitialProject",
"result_terms": [
{
"expr": "self",
"star": true
}
]
}
]
}
}
]
},
{
"#operator": "Order",
"sort_terms": [
{
"expr": "(`public_portal`.`_id`)"
}
]
},
{
"#operator": "Offset",
"expr": "24"
},
{
"#operator": "Limit",
"expr": "24"
},
{
"#operator": "FinalProject"
}
]
}
],
"status": "success",
"metrics": {
"elapsedTime": "6.755603ms",
"executionTime": "6.573912ms",
"resultCount": 1,
"resultSize": 2972
}
}
這與4000x5記錄完成的。
「收集」就是我所說的「類型」。
由於某種原因,它不再超時,它只是不返回任何內容。如果沒有ORDER BY,它會快一點,但我需要它。我會等4.5.0。 –