rdbms

I have read the following text in a technical blog discussing the advantages and disadvantages of NoSQL " For years, in order to improve performance on database servers, database administrators have had to buy bigger servers as the database load increases (scaling up) instead of distributing the database across multiple “hosts” as the load increases (scaling out). RDBMS do not typically scale out easily, but the newer NoSQL databases are actually designed to expand easily to take advantage of new nodes and are usually designed with low-cost commodity hardware in mind. " I became confused about

Is it possible to get the size in bytes of the results of an sql query in MySQL? For example: select * from sometable; ths returns 10000 rows. I don't want the rows but the size of the resultset in bytes. Is it possible? select sum(row_size) from ( select char_length(column1)+ char_length(column2)+ char_length(column3)+ char_length(column4) ... <-- repeat for all columns as row_size from your_table ) as tbl1; char_length for enum , set might not accurate, please take note To build on Angelin's solution, if your data contains nulls, you'll want to add IFNULL to each column: select sum( ifnull

So I recently learned about ASSERTION in my databases course, and my prof noted that major databases don't support it, even though it is in the SQL-92 standard. I tried googling to find out why, but there doesn't seem to be any discussion on the topic. So, why isn't ASSERTION supported by the vast majority of relational database packages? Is it soley a performance issue or is there something intrinsically hard about it? If you can, please note any database packages that implement it as well (example: if there's an academic/teaching DB). Also, why is there so little discussion on the issue; it

Why are batch inserts faster? Is it because the connection and setup overhead for inserting a single row is the same for a set of rows? What other factors make batch inserts faster? How do batch updates work? Assuming the table has no uniqueness constraints, insert statements don't really have any effect on other insert statements in the batch. However, during batch updates, an update can alter the state of the table and hence can affect the outcome of other update queries in the batch. I know that batch insert queries have a syntax where you have all the insert values in one big query. How do