optimizer

美 　英

• 網(wǎng)絡(luò)優(yōu)化器；優(yōu)化程序；查詢優(yōu)化器

例句

Due to the interplay of these diverse independent factors, in rare instances, the optimizer might select less than optimal execution plans.

在這些不同的獨立因素的相互作用下，優(yōu)化器可能會選擇不太優(yōu)化的執(zhí)行計劃。

Ideally, the optimizer would identify the most efficient access plan possible, but this goal is often impractical.

在理想情況下，優(yōu)化程序將盡可能地找出最為高效的訪問計劃，但這一目標(biāo)通常是不切實際的。

Note, however, that the optimizer is often unable to precisely estimate a query's cost, so expect there to be differences.

但是，請注意，優(yōu)化程序通常無法精確地預(yù)計查詢的成本，因此應(yīng)該會存在差異。

The output of the optimizer is a query execution plan, sometimes referred to as a query plan or just a plan.

優(yōu)化器的輸出稱為“查詢執(zhí)行計劃”，有時也稱為“查詢計劃”或直接稱為“計劃”。

You can use the REWRITE function without the ANSI argument to help understand how the optimizer generated the access plan for a given query.

使用REWRITE函數(shù)時可以不帶ANSI參數(shù)，這樣可以幫助理解優(yōu)化程序是如何生成給定查詢的訪問計劃的。

No degree of query optimizer intelligence can eliminate the resource cost of these constructs when compared to a less complex query.

與不太復(fù)雜的查詢相比，查詢優(yōu)化器的智能水平無法消除這些構(gòu)造的資源開銷。

The optimizer's estimate could be very close to the actual value as long as the data distribution has not changed since the last RUNSTATS.

只要數(shù)據(jù)分布自上一次RUNSTATS以后沒有改變，則優(yōu)化器的估計可能非常接近實際值。

Further, the solidDB query optimizer recognizes the different nature of the in-memory tables by estimating execution costs in a new way.

而且，solidDB查詢優(yōu)化器通過以一種新的方式估計執(zhí)行成本，判別內(nèi)存中的表的不同性質(zhì)。

It is possible that the query optimizer might have generated a remote statement that hits the remote server's limitation on performance.

查詢優(yōu)化器有可能生成與遠程服務(wù)器的性能限制有沖突的遠程語句。

Predicates with concrete values are important for the optimizer to be able to use available distribution statistics.

為使優(yōu)化器能夠使用可用的分布統(tǒng)計信息，帶有具體值的謂詞極為重要。

If the execution plan problems cannot be avoided, guidelines can be used to affect the optimizer plan to mitigate the performance problems.

如果無法避免執(zhí)行計劃中出現(xiàn)的問題，那么可以使用準(zhǔn)則來影響優(yōu)化器計劃，從而解決性能問題。

The optimizer uses MAGIC values as a last resort when it is unable to accurately predict the selectivity of a predicate .

當(dāng)優(yōu)化程序不能準(zhǔn)確判定一個謂詞的選擇性時，它的最后一個手段就是利用MAGIC值。

Many customers new to Informix do not realize they must update statistics, and see poor performance due to the lack of optimizer statistics.

許多Informix新客戶沒有認識到他們必須更新統(tǒng)計數(shù)據(jù)，因此由于缺少最新的優(yōu)化器統(tǒng)計數(shù)據(jù)，他們的數(shù)據(jù)庫性能很差。

An entry is added to the system catalog to indicate to the query optimizer that such a remote index exists.

一個條目被添加到系統(tǒng)編目中，以向查詢優(yōu)化器表明存在那樣的一個遠程索引。

Up-to-date statistics allow the optimizer to accurately assess the cost of different query plans, and choose a high-quality plan.

最新的統(tǒng)計信息允許優(yōu)化器準(zhǔn)確地估計不同查詢計劃的開銷，并選擇高質(zhì)量的計劃。

If the best indexes do not exist, the query optimizer generates a suboptimal query plan, but still stores information about these indexes.

如果不存在最佳索引，則查詢優(yōu)化器將生成非最佳查詢計劃，但會存儲有關(guān)這些缺失的最佳索引的信息。

The optimizer depends on accurate cardinality estimates to properly compute the cost of each query access plan considered.

優(yōu)化器憑借精確的基數(shù)估計值來準(zhǔn)確計算出每一個待定查詢訪問計劃的成本。

db2exfmt is typically used for comprehensive performance analysis, as it provides the most optimizer information.

db2exfmt通常用于廣泛的性能分析，因為它提供了大部分優(yōu)化器信息。

Information returned by sys. Dm_db_missing_index_details is updated when a query is optimized by the query optimizer, and is not persisted.

由sys.dm_db_missing_index_details返回的信息會在查詢優(yōu)化器優(yōu)化查詢時更新，因而不是會持久化的。

Specifies the name or ID of the indexes to be used by the query optimizer when it processes the statement.

指定查詢優(yōu)化器處理語句時要使用的索引的名稱或ID。

Instead, the optimizer gathers up-to-date statistics on every database table referenced in a query.

相反，優(yōu)化器將對查詢中引用的每個數(shù)據(jù)庫表收集最新的統(tǒng)計數(shù)據(jù)。

Think of the optimizer as an explorer waiting to navigate a mountain represented by the data in the system.

可以將優(yōu)化器視為一個勘探器，正在系統(tǒng)中的數(shù)據(jù)所代表的大山中進行定位。

Unlike other heart-failure devices , the Optimizer works by strengthening the pumping force of the heart.

和其他治療心衰裝置不同的是，優(yōu)化裝置增強心臟泵血能力。

You can access the results and reports of various statistics within Google Website Optimizer to see which variant is the most effective.

你可以通過查看google網(wǎng)頁優(yōu)化工具的統(tǒng)計結(jié)果和報告，來判斷哪一種頁面變化能最有效率地提升轉(zhuǎn)化率。

WideVine was a video optimizer and one of the last major independent digital rights managers.

WideVine是一家視頻優(yōu)化公司，也是最后一批主要的獨立數(shù)字版權(quán)管理者之一。

An estimate source of Guess indicates that the optimizer has no selectivity information to use .

如果查詢被確定為是簡單查詢，則不會顯示選擇性統(tǒng)計信息，這樣將繞過優(yōu)化程序。

Almost every major database today uses some method of updating catalog statistics to provide the best information possible to its optimizer.

現(xiàn)在，幾乎所有重要數(shù)據(jù)庫都使用某種方法來更新目錄統(tǒng)計信息，以便為其優(yōu)化器提供可能的最佳信息。

The view does not have to be referenced in the query for the optimizer to consider that view for a substitution.

要使優(yōu)化器考慮將該視圖作為替換，并不需要在查詢中引用該視圖。

WebSphere Federation Server uses its cost-based optimizer to determine the most efficient means of resolving the multi-source query.

WebSphereFederationServer使用它的基于成本的優(yōu)化器決定執(zhí)行多源查詢的最有效的方式。

The query optimizer, in consultation with the wrapper, determines how the data is to be accessed.

查詢優(yōu)化器與包裝器一道決定如何訪問數(shù)據(jù)。

This set is input to the cost-based optimizer that decides whether to use any of the eligible indexes or not.

將該組索引輸入到基于成本的優(yōu)化器，這個優(yōu)化器決定是否使用任何合適的索引。

If such a plan is not possible , the query optimizer returns an error instead of deferring error detection to query execution .

如果不能使用這樣的計劃，查詢優(yōu)化器將返回錯誤而不是延遲對查詢執(zhí)行的錯誤檢測。

The optimizer will compare the cost of each method to determine the best one to use.

優(yōu)化器將比較每種方法的成本，確定使用最好的一種。

Updating index statistics to make sure the query optimizer has up-to-date information about the distribution of data values in the tables.

更新索引統(tǒng)計信息，確保查詢優(yōu)化器含有關(guān)于表中數(shù)據(jù)值分布的最新信息。

Application developers have to be careful, as in certain situations distribution statistics are important for the DB2 optimizer.

應(yīng)用程序開發(fā)人員必須小心謹慎，因為在某些情況下分布統(tǒng)計信息對于DB2優(yōu)化器來說非常重要。

If you do not implement UPDATE STATISTICS, the optimizer has inaccurate data to determine access paths.

如果沒有運行UPDATESTATISTICS，則優(yōu)化器只能使用不準(zhǔn)確的數(shù)據(jù)來確定訪問路徑。

This command updates the statistics in the system catalogs that the optimizer uses to determine the lowest-cost query plan.

此命令更新了系統(tǒng)目錄中的統(tǒng)計數(shù)據(jù)，優(yōu)化程序使用這些數(shù)據(jù)來確定成本最低的查詢計劃。

Tuning such an environment by only analyzing the optimizer plans is not feasible due to the quantity of produced plans.

由于所產(chǎn)生的計劃數(shù)量太多，僅通過分析優(yōu)化器計劃來調(diào)優(yōu)該環(huán)境是不可行的。

When cursors generate a keyset for a result set, the query optimizer estimates the number of rows that will be returned for that result set.

游標(biāo)為某個結(jié)果集生成鍵集時，查詢優(yōu)化器將估計為該結(jié)果集返回的行數(shù)。

The total cost to the query optimizer for executing this operation and all operations preceding it in the same subtree.

查詢優(yōu)化器執(zhí)行此操作及同一子樹內(nèi)位于此操作之前的所有操作的總開銷。