“I let the cat out of the bag about their wedding plans.”ĩ. ‘Let the cat out of the bag’ – to accidentally reveal a secret. ‘A piece of cake’– something is very easy.Ĩ. “Fuel these days costs and arm and a leg.”ħ. ‘To cost an arm and a leg’– something is very expensive. ‘When pigs fly’ – something that will never happen.Ħ. “I only go to the cinema once in a blue moon.”ĥ. ‘Once in a blue moon’ – an event that happens infrequently. “They finally saw eye to eye on the business deal.”Ĥ. ‘See eye to eye’ – this means agreeing with someone. “Hi Tom, speak of the devil, I was just telling Sara about your new car.”ģ. ‘Speak of the devil’ – this means that the person you’re just talking about actually appears at that moment. “By working part-time and looking after her kids two days a week she managed to get the best of both worlds.”Ģ. ‘The best of both worlds’ – means you can enjoy two different opportunities at the same time. Now with even more idioms and phrases added! Here are the most common English idiomsand phrases that will enrich your English vocabularyand make you sound like a native speaker. That is why we have gathered some of the most common English idioms and phrases so you will understand the true meaning of them. If you can’t understand idioms you will not be able to understand the context. When you learn English idioms and phrases you will sound more confident especially when you speak with native English speakers. To learn English idioms and expression it can take some time but there are some of them that are more popular than others that will come handy if you know them. You have probably heard some of them, especially in TV-shows and movies, and wondered why you can’t understand these idioms even though you fully understand the words.

Most of the English idioms you hear are offering advice’s but also contain some underlying principles and values. Idioms are words or phrases that aren’t meant to be taken literally and usually have a cultural meaning behind them. Even with 100,000 rows, the run time only increased to 0.647 seconds.Every language has its own idioms and expressions and the English language has plenty of phrases that is useful to learn. With 10,000 rows, the run time was only 0.059 seconds. Using multi-value insert statements with 250 rows per batch, it was able to complete the 10,000-row test in as little as 1.2 to 1.7 seconds.įor even better performance, we can turn to database-specific techniques such as SqlBulkCopy. In the interest of completeness, ADO.NET without an ORM was also tested. Once you add the cost of network latency, the sizes of the batches should be increased to reduce the number of round-trips to the database. As mentioned above, this was using a local database. But the drop from the worst case of 2 seconds to a best case of 1.4 seconds may not be significant enough to consider.ĭoes this mean you should automatically start using batches of 100? Not necessarily. Zooming in, you can see that batch size does have a small effect on EF Core.Īgain, a batch size of roughly 100 improves performance. This is just an illusion caused by the dramatic increase in run time EF 6 experiences with batch size. When looking at the chart, you may have noticed that EF Core appears to have a straight line. As the line labeled “EF 6 B” shows in the chart below, the frequency in which you call SaveChangeshas no effect. Instead of creating a new DBContext for each batch, only one DBContext was used with SaveChangesbeing called between batches. In order to determine whether this was actually caused by context fouling, the same test was run again with one modification. In the timings above, a new DBContext was created for each batch. Coincidentally, a batch size of 250 likewise takes about six and a half seconds. Below that, the run time starts increasing again with a batch size of 25 requiring 6.3 seconds. This progression continues until approximately 100 batches of 100 rows each, which only takes 1.4 seconds. Batches of 1,000 further reduces the run time to roughly 19 seconds. Using two batches of 5,000 reduced the total time to 82 seconds.

Since this is a local sever, the network latency is negligible. When performed in a single batch, it took over 160 seconds. This can be hard to see during testing if the number of records is small, but the cost increases proportionally to the number of objects stored in the change tracking system.įor this test, 10,000 rows were inserted into a table with eight columns on a local server.

The longer you use a single DBContext object, the slower it becomes. When working with EF 6, a problem you may have experienced is context fouling. None are so readily apparent as when dealing with large collections. Entity Framework Core (EF Core) offers significant performance improvements over Entity Framework 6 (EF 6).

Ef collection