massive whiteboard

Because of the need for work, deep learning is needed to identify malicious binary files, so crawl some resources.#-*-Coding:utf-8-*-import requestsimport reimport sysimport loggingreload (SYS) sys.setdefaultencoding (' Utf-8 ') Logger = Logging.getlogger ("Rrjia") formatter = logging. Formatter ("% (asctime) s-% (name) s-% (levelname) s-% (message) s") File_handler = logging. Filehandler ("/home/rrjia/python/test.log") File_handler.setformatter (Formatter) Logger.addhandler (File_handler) Logge

Business requirements: the need to migrate 1000多万个 files from one directory to a remote machineIdea: Use wget to move the file one after another, because the number of files is relatively large, if a bit in the loop operation, it will be very slow. So the batch operation, adopt piecemeal method.#!/bin/shhome=/usr/local/www/skate/image63delbackcd $home if[ ' pwd ' == $home ];thena= "110000002000000 3000000400000050000006000000700000080000009000000 " forbin $a doc= ' expr $b +100000 ' forloopin '

With the construction of "Golden Shield project" and the rapid development of public security informationization, the computer application system of public security is widely used in various duties and departments. At the same time, the core of application system system, the storage of system data-database also with the actual application and rapid expansion, some large-scale systems, such as the population system more than 10 million data, can be described as

Massive data comparisons to eliminate repetitive solutions Recently has a Beijing to do the mail marketing friend, his hand many millions of data, needs to do eliminates the duplication processing. Here are some of the solutions I found in my groping process for your reference: 1: Write your own program to achieve: This functionality can be implemented, but the technology involved is cumbersome and time-consuming: 1 basic knowledge of set operations 2

author in practice, found that top is really good and efficient. But this word is not in another large database Oracle, which cannot be said to be a pity, although it can be solved in Oracle in other ways, such as: RowNumber. We'll use the top keyword in a future discussion of "Implementing TENS data paging display stored procedures." So far, we've discussed how to quickly query out the data methods you need from a large-capacity database. Of course, we introduce these methods are "soft" method

Tags: mysql database go heavyBecause the work needs to carry on the data to weigh, therefore does the record, actually is very small white question ....In fact, in terms of data deduplication, the best thing is to design the program and database when the data redundancy is considered, do not insert duplicate data. But,,,, this project, if two of the fields are duplicated at the same time, even if redundant, but also need to self-growing ID as the primary key convenient query .... So ... Forget i

and truncate carefully, especially when there is no backup. Otherwise, it's too late to cry.6. On the use, want to delete some data rows with delete, note with the WHERE clause. The rollback segment should be large enough. If you want to delete a table, delete all of the data by dropping it to keep the table. If it is unrelated to the transaction, use truncate. If it is related to a transaction, or if you want to trigger trigger, or delete the fragment inside the table, you can use truncate to

method, you should first look for a set-based solution to solve the problem, and the set-based approach is usually more efficient. 27. As with temporary tables, cursors are not unusable. Using Fast_forward cursors on small datasets is often preferable to other progressive processing methods, especially if you must reference several tables to obtain the required data. Routines that include "totals" in the result set are typically faster than using cursors. If development time permits, a cursor-b

Recently, due to the need for work, we began to focus on the relative optimization of select query statements for MySQL databases. Because of the actual project involved, it is found that when the data volume of MySQL table reaches millions, the efficiency of normal SQL query decreases linearly, and the query speed is simply intolerable if the query condition in where is more. Once tested on a table containing 400多万条 records (indexed) to perform a conditional query, its query time unexpectedly u

solution to solve the problem, and the set-based approach is usually more efficient. 27. As with temporary tables, cursors are not unusable. Using Fast_forward cursors on small datasets is often preferable to other progressive processing methods, especially if you must reference several tables to obtain the required data. Routines that include "totals" in the result set are typically faster than using cursors. If development time permits, a cursor-based approach and a set-based approach can all

command line, such as the file "Testfile" in the database, which can be done as follows. First of all, let's meet Mongofiles in general:instance to store files in the databasedb.fs.files.find () parameter description:FileName: The name of the stored file;size of the Chunksize:chunksuploaddate: Storage TimeMD5: MD5 code of the fileLength: Size of file (in bytes)Db.fs.chunks.find () parameter description:N: The serial number representing the chunks, which starts from 0;The data field is actually

bulk binding (bulk binding). When looping through SQL statements that execute a bound variable, a large number of context switches occur in PL/SQL and in the engines (switches). With bulk binding, data can be batched from the Plsql engine to the SQL engine, reducing the context switching process and improving efficiency. This method is more suitable for online processing without downtime.7. Sqlplus-s user/pwdSet Copycommit 2;Set ArraySize 5000;Copy from User/[email protected]-To

the development of the high speed? Assuming a composite query, my lightweight framework is useless. Paging string you have to write it yourself, how much trouble? Here we look at a sample, the idea comes out:SELECT * from collect where ID in (9000,12,50,7000); 0 seconds to check it out!Mygod, MySQL's index is actually the same as the in statement valid!It seems that the online say in cannot be indexed is wrong!With this conclusion, it is very easy to apply to the lightweight framework:With simp

(1000); ResultSet rs = ps.executequery (); int i = 0; while (Rs.next ()) {i++; if (i% = = 0) {SYSTEM.O Ut.println (i); }}} catch (ClassNotFoundException e) {e.printstacktrace ();} catch (SQLException e) {e.printstacktrace ();} } } This time again, we found that there was no card at all. Sentiment: Similar to the problem of slowly tracking code, more important is to have colleagues around the need to discuss each other, forming an atmosphere, because the process is very boring, it is difficult t

out:SELECT * from collect where ID in (9000,12,50,7000); 0 seconds to check it out!Mygod, MySQL's index is also valid for in statements! It seems that the online say in cannot be indexed is wrong!With this conclusion, it is easy to apply the lightweight framework:With a simple transformation, the idea is simple:(1) by optimizing the index, find the ID, and spell "123,90000,12000″ such a string."(2) The 2nd query finds the results. Small index + a little bit of change makes it possible for MySQL

Label:Reference: Http://stackoverflow.com/questions/93128/mysql-error-1153-got-a-packet-bigger-than-max-allowed-packet-bytesWrite test data with a script, OK on Ubuntu, did not expect the CentOS 1153 error. Workaround:Log in to MySQL and execute:Set global net_buffer_length=1000000; Set global max_allowed_packet=1000000000; It's OK.If it is a SQL script, you can import it with the following commandMySQL--max_allowed_packet=100m-u root-p Database CentOS MySQL

Massive Data Query progress waiting, Data Query progress The main code. Modify it according to the actual situation. Response. write (" In addition, you need to add the namespace using System. Threading;

the frequent call business, as far as possible within the local process, for example, for the client call API setting alias and subscription topic, First check that the cache has been set, only if there is no setting to send back-end service, after optimization, the business pressure of the backend service is greatly reduced.some insights in the development of millet push processServices to support horizontal scaling, as far as possible to be stateless, or use a consistent hash of the partition

Experience in using SqlBulkCopy (massive data import) and experience in using sqlbulkcopy Article reprinted original address: http://www.cnblogs.com/mobydick/archive/2011/08/28/2155983.html Recently, due to the lazy work of previous designers, the extended information of a table is stored in a "key-value" table instead of in the paradigm. For example: For each piece of information in the primary table, there are about 60 "keys". That is to say, each

In asp and php, textarea submits a solution for massive data loss. I used textarea to submit a large amount of data. I started to select mediumtext for the field type. when the data was lost, I changed it to longtext, and the data was still lost, in addition, it was found that mediumtext and mediumtext were submitted to a large amount of data I submitted using textarea. Mediumtext is selected as the field type and data is lost. Later I changed it to l