salami slicing

Chapter 1th IntroductionWith the widespread popularization of Internet application, the storage and access of massive data has become the bottleneck problem of system design. For a large-scale Internet application, billions of of PV per day is undoubtedly a very high load on the database. The stability and scalability of the system caused great problems. With data slicing to improve site performance, scaling out the data layer has become the preferred

1 What is the basic idea of a sub-database table?It is literally a simple way to store data that is stored in a single library on multiple libraries, storing data that was originally stored in a single table on multiple tables.2 Why should the basic idea be divided into sub-tables?The amount of data in the database is not necessarily controllable, in the case of no sub-database, with the development of time and business, the table in the library will be more and more, the amount of data in the t

Tags: blog http java using OS IO file dataThis article reproduced: http://www.cnblogs.com/olartan/archive/2009/12/02/1615131.htmlChapter 1th IntroductionWhen the amount of data is large, the multiple tables are divided into different db first, then the data is distributed to different databases according to the key columns. After the library distribution, the system query, IO and other operations can have a group of multiple machines together to complete. This article is mainly aimed at, the mas

tables are kept to a maximum, and the degree of freedom of writing SQL is guaranteed. Not easily restricted by clauses such as join, group BY, order by, and so on.2.2If the amount of tabular data is large and rapid, it needs to be further divided horizontally. Further horizontal segmentation is done in this way:2.2.1In combination with business logic and inter-table relationships, the current shard is divided into smaller shard, typically these smaller shard each contain only one primary table

1 What is the basic idea of a sub-database table?It is literally a simple way to store data that is stored in a single library on multiple libraries, storing data that was originally stored in a single table on multiple tables.2 Why should the basic idea be divided into sub-tables?The amount of data in the database is not necessarily controllable, in the case of no sub-database, with the development of time and business, the table in the library will be more and more, the amount of data in the t

and installs a single application variation based on the device model. (Supported by iOS9.0.2 or later) For backward compatibility, iOS apps now contain both 32-bit and 64-bit slice. In terms of image resources, there are all 2x 3x images available (1x is not needed now ). When users use an app, because the device is specific, they only need a set of resources. However, the entire app package is downloaded during purchase and download. Apple finally realized how silly it was. In iOS 9, you can

The PS switch page may sometimes encounter this situation: the design has been changed, but the slice should be the same as before.If you can directly use the previously cut slice, you can save a lot of time to re-partition the slice. However, the designer does not modify the PSD of the last slice, but outputs a new PSD.Can I copy the sliced part in a PSD to another PSD?Unfortunately, currently, PS CS6 still does not support copying slices between multiple windows. You can only copy slices

specified axis. That is, to delete the meaning of a Series element or a row (column) of DataFrame.drop(labels, axis=0)Method: >>> serd 4.5b 7.2a -5.3c 3.6dtype: float64>>> df Ohio Texas Californiaa 0 1 2c 3 4 5d 6 7 8[3 rows x 3 columns]>>> ser.drop('c')d 4.5b 7.2a -5.3dtype: float64>>> df.drop('a') Ohio Texas Californiac 3 4 5d 6 7 8[2 rows x 3 columns]>>> df.drop(['Ohio','

Get married with python and fall out of favor(Python) Python was first recognized because of its exposure to 3D printing. After a period of understanding about 3D printing, it learned that Cura, the industry's most famous open-source Slicing Software, was built using Python and WXpython. Because our company uses the open-source Slicing Software Cura and wants to own its own

very easy. If you haven't tried it yet, you can try it now. You can not only pass the sequence directly to the constructor, but also pass the variables with tuples or strings to the list constructor. Obviously, the main reason why a sequence is useful is that it can easily access entries in the sequence. If you still remember the discussion of tuple, you can know that you can access an entry at a time in the sequence or by slicing the entry. Python l

Https://www.liaoxuefeng.com/wiki/0014316089557264a6b348958f449949df42a6d3a2e542c000/ 0014317568446245b3e1c8837414168bcd2d485e553779e000In Python, the more code is better, the less the better. The more complex the code is, the better it is, but the simpler the better.Based on this idea, we introduce the very useful advanced features in Python, the functionality that 1 lines of code can implement,Never write 5 lines of code. Always keep in mind that the less code you have, the more efficient your

characteristics and advantages of the store, and carefully dressed words, can be decorated by the store with a variety of promotional means to attract buyers eye, build a good shopping environment ha. So in the case of a single business has not been made, the application opened a Wang shop. Here are two tips for the first time you found the homepage of the Wang shop. Tips One, use fireworks and FrontPage to make simple links with pages Fireworks is a good image production tool Macromedia, co

we are doing the site or decorate the shop, often to add hyperlinks for text, this more use is for the homemade navigation bar picture text plus linked URLs, to do all of this generally requires DW software, and on hand only PS how to do? Now let's talk about how to add a link to the picture text with PS. Method/Step First open the PS software, a new 1024 pixel X50 pixel navigation bar, and then use the coloring button to paint your favorite color, as shown in the picture: Then,

PS Slicing tool, is a very useful function, it can be based on your needs to intercept any part of the picture, while a picture can be cut multiple places. PS slices can be saved as the time to save the parts you cut to a separate picture, completely separate from each other. So, when making a Web page or intercepting a part of a picture, this tool is often used. And if you do a page, or you want to do a website, you may use this

The bytes package provides a series of functions for reading and writing byte slices The function of byte slicing is more, it is divided into basic processing function, comparison function, suffix check function, index function, partition function, Case-handling functions and sub-slice handlers, and so on. 1. Byte slicing basic processing function API 1.1Contains () function // The function of the Co

contents of the Activea-authors table are laws and regulations that are in force, are often used, while the Inactive-law table makes obsolete regulations less frequently queried. Horizontal partitioning adds complexity to your application, and it usually requires multiple table names at query time, and the union operation is required to query all data. In many database applications, this complexity outweighs its advantages because, as long as the index keyword is not large, when the index is us

table: vertical slicing and horizontal slicing.3.1 What is vertical slicing, which divides the table into different libraries according to the function module and the close degree of the relationship. For example, we will establish the definition of database WORKDB, commodity database paydb, user database UserDB, log database logdb, respectively, for storing Pro

1 What is the basic idea of a sub-database table?It is literally a simple way to store data that is stored in a single library on multiple libraries, storing data that was originally stored in a single table on multiple tables.2 Why should the basic idea be divided into sub-tables?The amount of data in the database is not necessarily controllable, in the case of no sub-database, with the development of time and business, the table in the library will be more and more, the amount of data in the t

Tags: horizontally split mysql Database1, the introduction of horizontal splittingIn general, simple horizontal slicing is the main way to spread an extremely mundane table into multiple tables, with a subset of the data in each table, according to some rule of a field. In simple terms, we can interpret the horizontal segmentation of the data as a segmentation of the data rows, that is, some of the tables in theRows are sliced into one database, and s

(DF)# pd.to-datetime can also process missing values and automatically turn to NAT (not a time)timestring = TimeString + [None]DF = Pd.to_datetime (timestring)Print (DF)Print ('------------------------------------------------↑, section1\n\n ')# 2, Time series basics# Pandas the most basic time series type is a series with a timestamp (timestamp) indexdates = [Datetime.strptime (' 2000/1/' + str (i), '%y/%m/%d ') for I in range (1, 11)]Print (dates)TS = PD. Series (Np.random.randn (Ten), index=d