如何正确使用spring数据的二级索引

Question

我有一个名为order的couchbase bucket，其中包含将近2000个文档，我为此bucket创建了一个二级索引（idx_customer），以优化我的查询：

在couchbase查询监视器中执行时，查询命中索引。

但我认为，当从spring数据存储库播放时，它错过了索引。这主要是因为存储库中的排序和分页使我的查询在其他没有索引的查询中被翻译。

CREATE INDEX idx_customer ON `order` (
buyer.contact.firstName , 
buyer.contact.lastName , 
ALL DISTINCT ARRAY aoc.`communicationValue` FOR aoc IN buyer.contact.communicationChannel
WHEN aoc.`communicationChannelCode`= "EMAIL" END)
WHERE _class = "com.lbk.entities.OrderEntity"

我使用此存储库中的spring数据在spring boot应用程序中查询订单：

import com.lbk.entities.OrderEntity;
import com.lbk.entities.OrderMetadataEntity;
import org.springframework.data.couchbase.core.query.N1qlPrimaryIndexed;
import org.springframework.data.couchbase.core.query.N1qlSecondaryIndexed;
import org.springframework.data.couchbase.core.query.Query;
import org.springframework.data.couchbase.core.query.ViewIndexed;
import org.springframework.data.couchbase.repository.CouchbasePagingAndSortingRepository;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;

import java.util.List;

@ViewIndexed(designDoc = "orderEntity")
@N1qlSecondaryIndexed(indexName = "idx_customer")
@N1qlPrimaryIndexed
public interface OrdersRepository extends CouchbasePagingAndSortingRepository<OrderEntity, String> {

    List<OrderMetadataEntity> findAllBy();

    Page<OrderMetadataEntity> findAllBy(Pageable page);

    @Query("#{#n1ql.selectEntity} WHERE #{#n1ql.filter} "
                    + "AND orderTypeCode = $1 "
                    + "AND (orderCategory != $2 OR orderCategory is not valued ) "
                    + "AND buyer.contact.firstName is not null"
    )
    Page<OrderMetadataEntity> findOrders(String orderTypeCode, String excludedOrderCategory, Pageable page);

    @Query("#{#n1ql.selectEntity} WHERE #{#n1ql.filter} "
                    + "AND creationDateTime >= STR_TO_MILLIS($1) AND creationDateTime <= STR_TO_MILLIS($2) "
                    + "AND orderTypeCode = $3 "
                    + "AND (orderCategory != $4 OR orderCategory is not valued )"

"ANDbuyer.contact.firstName is not null"）Page findOrdersByCreationDateTime在（String start， String end， String orderTypeCode， String排除dOrderClass，可分页页面）；

}

但是性能和日志记录显示，对于sur，我没有使用索引，这是怎么了？如何查询正确的二级索引形成我的存储库？

对于此分页N1QL查询：

@Query("#{#n1ql.selectEntity} WHERE #{#n1ql.filter} "
                                + "AND orderTypeCode = $1 "
                                + "AND (orderCategory != $2 OR orderCategory is not valued ) "
                                + "AND buyer.contact.firstName is not null")
Page<OrderMetadataEntity> findOrders(String orderTypeCode, String excludedOrderCategory, Pageable page);

我在日志中有三个查询：

1. 查询统计文档。
2. 查询获取文档的第一页。
3. 查询获取子文档（SELECTARRAY_LENGTH（orderLineItem））（我想知道为什么！！！）。

以下是Spring数据日志：

Executing N1QL query: {\"args\":[\"%mohammed%\",\"%mohammed%\",null,\"220\",\"EXECLUDED_CATEGORY\"],\"statement\":\"SELECT COUNT(*) AS count FROM `order` WHERE `_class` = \\"com.lbk.entities.OrderEntity\\" AND ( LOWER(buyer.contact.firstName) LIKE $1 OR LOWER(buyer.contact.lastName) LIKE $2 OR ANY communicationChannel IN buyer.contact.communicationChannel SATISFIES ( communicationChannel.communicationChannelCode = 'EMAIL' AND communicationChannel.communicationValue  = $3 ) END )  AND orderTypeCode = $4 AND (orderCategory != $5 OR O2.orderCategory is not valued )AND creationDateTime in (select RAW max(O2.creationDateTime) from `order` O2 WHERE ( LOWER(O2.buyer.contact.firstName) LIKE $1 OR LOWER(O2.buyer.contact.lastName) LIKE $2 OR ANY communicationChannel IN O2.buyer.contact.communicationChannel SATISFIES ( communicationChannel.communicationChannelCode = 'EMAIL' AND communicationChannel.communicationValue  = $3 ) END )  AND ANY communicationChannel IN O2.buyer.contact.communicationChannel SATISFIES ( communicationChannel.communicationChannelCode = 'EMAIL' AND communicationChannel.communicationValue is not null ) END AND O2.orderTypeCode = $4 AND (O2.orderCategory != $5 OR O2.orderCategory is not valued) group by ( ARRAY item.communicationValue FOR item IN O2.buyer.contact.communicationChannel WHEN item.communicationChannelCode = 'EMAIL' END ) )AND buyer.contact.firstName IS NOT NULL\",\"scan_consistency\":\"statement_plus\"}
Executing N1QL query: {\"args\":[\"%mohammed%\",\"%mohammed%\",null,\"220\",\"EXECLUDED_CATEGORY\"],\"statement\":\"SELECT META(`order`).id AS _ID, META(`order`).cas AS _CAS, `order`.* FROM `order` WHERE `_class` = \\"com.lbk.entities.OrderEntity\\" AND ( LOWER(buyer.contact.firstName) LIKE $1 OR LOWER(buyer.contact.lastName) LIKE $2 OR ANY communicationChannel IN buyer.contact.communicationChannel SATISFIES ( communicationChannel.communicationChannelCode = 'EMAIL' AND communicationChannel.communicationValue  = $3 ) END )  AND orderTypeCode = $4 AND (orderCategory != $5 OR O2.orderCategory is not valued )AND creationDateTime in (select RAW max(O2.creationDateTime) from `order` O2 WHERE ( LOWER(O2.buyer.contact.firstName) LIKE $1 OR LOWER(O2.buyer.contact.lastName) LIKE $2 OR ANY communicationChannel IN O2.buyer.contact.communicationChannel SATISFIES ( communicationChannel.communicationChannelCode = 'EMAIL' AND communicationChannel.communicationValue  = $3 ) END )  AND ANY communicationChannel IN O2.buyer.contact.communicationChannel SATISFIES ( communicationChannel.communicationChannelCode = 'EMAIL' AND communicationChannel.communicationValue is not null ) END AND O2.orderTypeCode = $4 AND (O2.orderCategory != $5 OR O2.orderCategory is not valued) group by ( ARRAY item.communicationValue FOR item IN O2.buyer.contact.communicationChannel WHEN item.communicationChannelCode = 'EMAIL' END ) )AND buyer.contact.firstName IS NOT NULL ORDER BY `creationDateTime` DESC LIMIT 18 OFFSET 0\",\"scan_consistency\":\"statement_plus\"}
Executing N1QL query: {\"args\":[\"069cf983-8ed7-4b8f-845d-175593d4ca49\"],\"statement\":\"SELECT ARRAY_LENGTH(orderLineItem) FROM `order` WHERE `_class` = \\"com.lbk.entities.OrderEntity\\" AND META().id = $1\",\"scan_consistency\":\"statement_plus\"}

谢谢

Answer 1

查询将无法使用idx_客户索引，因为它不符合条件。请在中签出“在Couchbase N1QL中为查询设计索引”https://blog.couchbase.com/n1ql-practical-guide-second-edition

该索引是部分索引，并且只有包含_class=“com.lbk.entities.OrderEntity”的文档的条目，但您的任何查询都不会包含此谓词，因此无法使用该索引。此外，查询谓词（谓词的每个或部分）必须使用hvae前导索引键作为查询谓词才能使用索引。对于日志中的查询，情况并非如此。如果需要，可以尝试使用非部分索引。

CREATE INDEX idx_customer1 ON `order` (_class, 
buyer.contact.firstName , 
buyer.contact.lastName , 
ALL DISTINCT ARRAY aoc.`communicationValue` FOR aoc IN buyer.contact.communicationChannel
WHEN aoc.`communicationChannelCode`= "EMAIL" END);