Female artists are beginning to learn Elasticsearch 了
See the circle of friends are reprinted ：
It shows that Elasticsearch The heat of the .
In recent years , Active in the Elasticsearch The Chinese community 、 Various QQ Study Group 、 Wechat learning group , We often see all kinds of problems , A lot of problems , The official documents are very clear , Even the official documents already have the answer .
Examples of emphasis in official documents ：
Avoid being right text Type used term query.
Avoid using the term query for text fields
search.allow_expensive_queries Set to false after ,wildcard Will not be carried out .
Wildcard queries will not be executed if search.allow_expensive_queries is set to false.
text Type storage data structure is inverted index , and geo and Numerical type storage data structure is BKD trees.
For example, text fields are stored in inverted indices, and numeric and geo fields are stored in BKD trees.
The above selection is aimed at the questions of wechat group ： Who knows the exact value is ES How is it stored in? No , such as "price": 100, Is it also stored in the inverted index ？
screwing Elasticsearch star
but , because Elasticsearch Quick update 、 Official documents are all in English 、 The coverage of official documents is comprehensive and extensive , Many beginners know it works , but , It's easy to be deterred .
Second best , Choose some old books or references , Wasted time 、 Took a lot of detours , And then through google、stackoverflow、disscuss.elastic.co、github Jump to the official document , It was then that I realized ：“ The document says , Why didn't I know ？！"
This article combines with myself Elastic Certification experience , Sort out Elasticsearch The learning path of official documents .
I hope it can help you .
The importance of first-hand information
Study Elasticsearch In the process of knowledge , Official English documents + Source code + Source code author's book + Only official blogs can be called first-hand information .
Second hand information ：github issue, Foreign community forum ,stackoverflow, Domestic blog forum , Excellent books at home and abroad .
The author part of the cover of the book , Writing 、 Huang, 、 The difference between translation （ The statement is not rigorous ）
1） Writing - I wrote it all by myself , The quality is relatively high . Very little reference is made to other people's . Such as ： Hou Jie 《 Explain profound theories in simple language MFC》、《 Self cultivation of programmers 》、《Elasticsearch Source code analysis and actual combat 》……
2） translate - Translation usually lags behind 1 year +, such as ：《Elasticsearch in action》 It's lagging behind 3 year .15 English version of ,18 Chinese version published in .
Third hand information ： A patchwork of domestic books .
The cover usually has “ Huang, ” word .
3） Huang, - There is no lack of excellent works . but , There are many doctoral advisors in China 、 Master Guide 、 The teacher and so on wrote a lot of bad books in order to evaluate the title , Never buy ！
How to identify a good book ？ Look at sales volume 、 Look at the score 、 Look at the reprint situation, you can basically distinguish between eight or nine .
by comparison ：
First hand data is better than second-hand data , Second hand data is better than third-hand data .
First hand information is very important , It is the most direct way to acquire knowledge , There is no middle link , Reduce cognitive blind areas and barriers ！
Elasticsearch Official documents are first-hand information
The less words , The more information ！
About Elasticsearch Official documents ,ES What do industry leaders say ？
newest + Enrich + authority + By spectrum
VIVO Search director Yang Zhentao pointed out that ：
“ First, it is based on the official introduction and reference documents , Because the industry is now ES The relevant information is relatively rich , But want to keep up with the latest official version and consider authority , Or official reference documents and related manuals will be more reliable ！”
Get a quick overview of , To be helpful to
Ctrip WOOD Uncle emphasizes ：
“ For beginners, the most simple and easy to understand , Or the official one Elasticsearc Authoritative guide , The Chinese version is 2.X, But get to know the novice quickly Elasticsearch The whole picture of , Very helpful ”.
Elasticsearch Official document address
Elasticsearch Official document entry of the latest version
Elasticsearch Authoritative guide in English （2.X）
Elasticsearch Chinese version of authoritative guide （2.X）
Elastic Stack All document entry
What's the difference? ？
《 Authoritative guide 》： emphasize Elasticsearch principle
《 Official documents 》： There are versions , Emphasis on comprehensiveness and detail API, It's a help document for your development and operation .
how Efficient learning Elasticsearch Official documents
First of all ： sense , Build global awareness from the big picture
Look at the modules ？
Nothing but ： Deploy 、 Indexes 、 retrieval 、 polymerization 、 analysis 、 file 、 colony 、 Security and other core modules .
Understand the whole document and chapter context in advance , avoid ： Only trees, not forests .
give an example ： Take care of query mapping aggs Where are we waiting , If something goes wrong, you can find it .
avoid ： Come up and see from the beginning to the end . And school days , Recite the words of CET-4 and CET-6 , Some students have taken the exam several times , The word still stays in a At the beginning abandon part .
second ： Practice looking up Elasticsearch Official documents
When you have a problem, go to the document , instead of google Or other search engines don't consider .
Although it's painful , But it works .
Anything that takes time to comb , I remember firmly . Other people give ready-made answers to short-term results , In the long run, I can't remember .
Practical examples ：
such as ： Have a problem Dynamic templates Just go to Google and search “elasticsearch Dynamic templates ”.
but , It's not learning 、 The best way to improve cognition .
We should think more about several issues , And look through the document with questions ：
0, English name is not dynamic template ？
1. Dynamic templates In that part of the document ？
2. Dynamic templates and mapping Or how other chapters relate ？
3, What is a dynamic template ？
4, Templates 、 What is the role of dynamic templates ？
5, Is there a static template ？
6, What's the relationship between dynamic templates and dynamic maps ？
7, How to use it in actual business ？ What kind of scene ？
8, Can you kibana dev-tool Knock demo Deepen the understanding ？
Third ： I can't find , To use Elasticsearch Document search function .
Practice and you will find ,Elasticsearch Official document search doesn't necessarily get the results you want . Gradually develop the habit of checking documents 、 Step by step, you're going to quit google、 I searched for it when I came up “ Bad ” habit .
Fourth ： adopt “ spot 、 Line 、 Noodles 、 body ”, Gradually build your own Elasticsearch system .
Encounter the knowledge that can't be , It is suggested that we go through the relevant knowledge points together , Enhance cognition .
Points form lines , Line into surface , The face forms the knowledge system .
give an example 1： Field type , Multiple field types make up mapping,mapping and setting Form a template , A template is a consideration for data modeling .
In turn, , From data modeling down to consider , The combination of the two is better .
give an example 2： Have a problem , Can split the problem into its own module , Search in the corresponding module .
There may be cross module , Don't be afraid of , Learn it together .
give an example 3：shard allocatin In both the index module and the cluster module , Both of them need to see , Let's deepen our understanding together ！
It was hard at first 、 Stick to it and you'll find it's reliable .
The basic problems we encounter every day ,80％ All of the above can be found in the documentation .
Elastic The content of the certification examination , After dismantling and carding ,90％ All of the above can be found directly or through links .
If , Can't find , I'm not familiar with it .
and Elastic The only reason why the certification test failed ： Not familiar with ！！！ If you're not familiar with , I'm sure I can't pass the exam ！
About Elasticsearch Document learning , common problem
Q1： It's hard to read English ？
There is no translation ？
If it doesn't work , You can read the translated version of the Chinese document first , Looking back at the English documents .
Q2： First look at the document and then practice , Or practice first and then turn over the document ？
On the direct look at the document , It's easy to miss the north , Especially when you don't understand , Will multiply the frustration .
therefore , Suggest ：
Combined with practice , If you encounter problems, you can improve the document quickly .
As mentioned earlier , Through a knowledge point , Connect other knowledge points , Form gradually “ spot 、 Line 、 Noodles 、 body ” The knowledge system of .
Of course , If you're preparing for a certification test , The two should be combined .
Q3： Be familiar with it ？
You can't be too familiar with .
Tencent pointed out that “ know sth. thoroughly by heart ” It's a little exaggerated , But the more familiar , The faster the problem is solved ！
I'm familiar , You can study the source code again 、 Study the bottom layer Lucene principle 、 Algorithm data structure principle .
about Elasticsearch Learning from , Official documents are just a basic link that cannot be bypassed .
Official documents can't cure everything , But it can definitely solve 80% Above questions .
We have better Elasticsearch Official document learning method , Welcome to leave a message .
about Elastic Stack, If love , Please love ！
author ：Elastic Certified Engineer / Alibaba cloud MVP / CSDN Blogger
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