difference between mysql and cassandra -

-

what difference between cassandra , mysql?

i searched using google. not satisfied, , not understand. please tell me clearly.

mysql relational database, supports complex, flexible queries using sql query language. relational model consists of tables (relations) can interlinked keys common multiple tables.

cassandra key-value store (like hashmap) lets plain or structured values based on key. not support complex/flexible queries, in return provides greater scalability , performance. not use fixed predefined tables, uses "column-based" model, each row of data can contain data items of various types, don't have predefined.

cassandra uses cassandra query language (cql) uses syntax similar sql. cassandra provides older binary query interface via thrift protocol.


Comments

Post a Comment

Popular posts from this blog

c# - how to write client side events functions for the combobox items -

-
<dx:aspxcombobox id="aspxcombobox2" runat="server" clientidmode="autoid" selectedindex="-1" onselectedindexchanged="aspxcombobox1_selectedindexchanged1" > <clientsideevents selectedindexchanged="function(s, e) { grid.selectrows();}" /> <items> <dx:listedititem text="selecte rows" /> <dx:listedititem text="unselectall" /> </items> </dx:aspxcombobox> i want write event "unselect all" item in combobox. how can this? you'll need write javascript function iterates thru combo-box , marks selected items false. see select/unselect checkbox fields using pure javascript , html sample code msdn:
Read more

exception - Python, pyPdf OCR error: pyPdf.utils.PdfReadError: EOF marker not found -

-
pypdf throws exception: pypdf.utils.pdfreaderror: eof marker not found i don't need fix pypdf, need eof error cause "except" block execute , skip on file, doesn't work. still causes program stop running. background: batch ocr program pdfs python, pypdf, adobe pdf ocr error: unsupported filter /lzwdecode ... saga continues. i got 10,000 pdfs in folder. ocrd, not. can't tell 'em apart. step 1 figure out ones not ocrd , ocr (see other threads details). so i'm using pypdf. exceptions related unrecognized characters , unsupported filters when try read text. guestimated if throws exception, it's got text in , doens't go in list. problem solved, right? so: pypdf import pdffilewriter, pdffilereader import sys, os, pypdf, re path = 'c:\users\homer\documents\my pdfs' filelist = os.listdir(path) has_text_list = [] does_not_have_text_list = [] pdf_name in filelist: pdf_file
Read more