Question

我有一个由针对oracle运行的实体框架生成的查询太慢了。它运行大约4秒钟。

这是我的查询的主要部分

var query = from x in db.BUILDINGs
                    join pro_co in db.PROFILE_COMMUNITY on x.COMMUNITY_ID equals pro_co.COMMUNITY_ID
                    join co in db.COMMUNITies on x.COMMUNITY_ID equals co.COMMUNITY_ID
                    join st in db.STATE_PROFILE on co.STATE_CD equals st.STATE_CD
                    where pro_co.PROFILE_NM == authorizedUser.ProfileName

                    select new
                    {
                        COMMUNITY_ID = x.COMMUNITY_ID,
                        COUNTY_ID = x.COUNTY_ID,
                        REALTOR_GROUP_NM = x.REALTOR_GROUP_NM,
                        BUILDING_NAME_TX = x.BUILDING_NAME_TX,
                        ACTIVE_FL = x.ACTIVE_FL,
                        CONSTR_SQFT_AVAIL_NB = x.CONSTR_SQFT_AVAIL_NB,
                        TRANS_RAIL_FL = x.TRANS_RAIL_FL,
                        LAST_UPDATED_DT = x.LAST_UPDATED_DT,
                        CREATED_DATE = x.CREATED_DATE,
                        BUILDING_ADDRESS_TX = x.BUILDING_ADDRESS_TX,
                        BUILDING_ID = x.BUILDING_ID,
                        COMMUNITY_NM = co.COMMUNITY_NM,
                        IMAGECOUNT = x.BUILDING_IMAGE2.Count(),
                        StateCode = st.STATE_NM,
                        BuildingTypeItems = x.BUILDING_TYPE_ITEM,
                        BuildingZoningItems = x.BUILDING_ZONING_ITEM,
                        BuildingSpecFeatures = x.BUILDING_SPEC_FEATURE_ITEM,
                        buildingHide = x.BUILDING_HIDE,
                        buildinghideSort = x.BUILDING_HIDE.Count(y => y.PROFILE_NM == ProfileName) > 0 ? 1 : 0,
                        BUILDING_CITY_TX = x.BUILDING_CITY_TX,
                        BUILDING_ZIP_TX = x.BUILDING_ZIP_TX,
                        LPF_GENERAL_DS = x.LPF_GENERAL_DS,
                        CONSTR_SQFT_TOTAL_NB = x.CONSTR_SQFT_TOTAL_NB,
                        CONSTR_STORIES_NB = x.CONSTR_STORIES_NB,
                        CONSTR_CEILING_CENTER_NB = x.CONSTR_CEILING_CENTER_NB,
                        CONSTR_CEILING_EAVES_NB = x.CONSTR_CEILING_EAVES_NB,
                        DESCR_EXPANDABLE_FL = x.DESCR_EXPANDABLE_FL,
                        CONSTR_MATERIAL_TYPE_TX = x.CONSTR_MATERIAL_TYPE_TX,
                        SITE_ACRES_SALE_NB = x.SITE_ACRES_SALE_NB,
                        DESCR_PREVIOUS_USE_TX = x.DESCR_PREVIOUS_USE_TX,
                        CONSTR_YEAR_BUILT_TX = x.CONSTR_YEAR_BUILT_TX,
                        DESCR_SUBDIVIDE_FL = x.DESCR_SUBDIVIDE_FL,
                        LOCATION_CITY_LIMITS_FL = x.LOCATION_CITY_LIMITS_FL,
                        TRANS_INTERSTATE_NEAREST_TX = x.TRANS_INTERSTATE_NEAREST_TX,
                        TRANS_INTERSTATE_MILES_NB = x.TRANS_INTERSTATE_MILES_NB,
                        TRANS_HIGHWAY_NAME_TX = x.TRANS_HIGHWAY_NAME_TX,
                        TRANS_HIGHWAY_MILES_NB = x.TRANS_HIGHWAY_MILES_NB,
                        TRANS_AIRPORT_COM_NAME_TX = x.TRANS_AIRPORT_COM_NAME_TX,
                        TRANS_AIRPORT_COM_MILES_NB = x.TRANS_AIRPORT_COM_MILES_NB,
                        UTIL_ELEC_SUPPLIER_TX = x.UTIL_ELEC_SUPPLIER_TX,
                        UTIL_GAS_SUPPLIER_TX = x.UTIL_GAS_SUPPLIER_TX,
                        UTIL_WATER_SUPPLIER_TX = x.UTIL_WATER_SUPPLIER_TX,
                        UTIL_SEWER_SUPPLIER_TX = x.UTIL_SEWER_SUPPLIER_TX,
                        UTIL_PHONE_SVC_PVD_TX = x.UTIL_PHONE_SVC_PVD_TX,
                        CONTACT_ORGANIZATION_TX = x.CONTACT_ORGANIZATION_TX,
                        CONTACT_PHONE_TX = x.CONTACT_PHONE_TX,
                        CONTACT_EMAIL_TX = x.CONTACT_EMAIL_TX,
                        TERMS_SALE_PRICE_TX = x.TERMS_SALE_PRICE_TX,
                        TERMS_LEASE_SQFT_NB = x.TERMS_LEASE_SQFT_NB
                    };

有一段代码可以解决查询中的动态where和sort子句，但是我已经把它们排除了。无论where和sort中的内容是什么，查询大约需要4秒钟。

我在Oracle中删除了生成的SQL，并且解释计划似乎没有显示任何尖叫的解决方法。费用是1554

如果不允许这样做，我道歉但似乎无法找到分享这些信息的好方法。我上传了Sql Developer生成的解释计划：http://www.123server.org/files/explainPlanzip-e1d291efcd.html

表格布局

Building
--------------------
- BuildingID
- CommunityId
- Lots of other columns

Profile_Community
-----------------------
- CommunityId
- ProfileNM
- lots of other columns

state_profile
---------------------
- StateCD
- ProfileNm
- lots of other columns

Profile
---------------------
- Profile-NM
- a few other columns

所有具有分配列的表每个都有120-150列。看起来实体正在生成一个select语句，它从每个表中提取每一列，而不仅仅是我想要的那一列。

让我烦恼的事情我认为可能是我的问题是在我的LINQ中我选择了50个项目，但生成的sql返回677列。我认为返回这么多列可能是我迟缓的源头。

为什么我在SQL中返回了如此多的列或者如何加快查询速度的任何想法？

Answer 1

我怀疑某些性能是否受到对象创建的影响。尝试运行查询而不只是一个基本的“选择x”，看看它是SQL查询需要时间还是创建对象。

此外，如果生成的查询过于复杂，您可以尝试将其分成较小的子查询，逐渐丰富您的对象，而不是尝试一次查询所有内容。

Answer 2

我最终创建了一个视图，并且视图只选择了我想要的列，并加入了需要在linq中加入的东西。

EF选择你试图加入的每个表中的每一列都很烦人。但我想我只注意到了这一点，因为我加入了一堆包含150多列的表格。

实体框架SQL选择600多列

2 个答案: