1Jan

Programma Dlya Rascheta Korpusa Sabvufera Na Russkom Yazike

1 CREATE TABLE COUNTER ( 2 type text, 3 actor text, 4 version bigint, 5 increment int, 6 PRIMARY KEY(type, actor, version)) Let’s say we have to keep count of how many shares of IBM are currently being traded in the market. CVRDT: 1 CREATE TABLE COUNTER ( 2 type text, 3 actor text, 4 version int, 5 increment int, 6 PRIMARY KEY(type, actor, version)) The above events will be captured as follows: 1 INSERT INTO COUNTER(type, actor, version, increment) VALUES('IBM', 'P1', 1, 1000); 2 INSERT INTO COUNTER(type, actor, version, increment) VALUES('IBM', 'P2', 1, 500); 3 INSERT INTO COUNTER(type, actor, version, increment) VALUES('IBM', 'P1', 2, 1500); Notice the difference in the last INSERT statement. Since this is a state-based CvRDT, the merge function will take the most recent value for each actor and calculate the sum of all the increments. 1 SELECT increment, version FROM COUNTER WHERE type = 'IBM' In this case, it will be 1500(for P1) + 500(for P2) = 2000. We can further optimize this using Cassandra’s last-write-wins policy if we use version as timestamp.

The new table model will be: 1 CREATE TABLE COUNTER ( 2 type text, 3 actor text, 4 increment int, 5 PRIMARY KEY(type, actor)) And the new insert statements updated as: 1 INSERT INTO COUNTER(type, actor, increment) VALUES('IBM', 'P1', 1000) USING TIMESTAMP 1; 2 INSERT INTO COUNTER(type, actor, increment) VALUES('IBM', 'P2', 500) USING TIMESTAMP 1; 3 UPDATE COUNTER SET increment = 1500 WHERE type = 'IBM' AND actor = 'P1' USING TIMESTAMP 2; As noted above, the merge function for a CvRDT will take the most recent value for each actor and calculate the sum of all the increments. As noted above, the merge function for a CvRDT will take the most recent value for each actor and calculate the sum of all the increments. 1 SELECT increment FROM COUNTER WHERE type = 'IBM' In this case, we just used Cassandra’s LWW policy to manage the most recent value for the actor. Pros: • Highly scalable since no coordination is required • No contention on inserts or updates • Associative and Commutative • Idempotent Cons: • Reads need to read all the records and take a sum • The row could get very wide which could slow down retrieval Garbage Collection As you can see with a CRDT, the rows could become very wide. Although Cassandra supports very wide rows, retrieval times could worsen as the number of events increase. The common way to address this in a CRDT is to have a garbage collector running in the background to periodically compact the row.

Cassandra requires the clocks to be in sync. The usual way to achieve this is using or Network Time Protocol. In order to mitigate clock skew, we will run a scheduler every n minutes and sum the increments until now – n and insert 1 consolidated CQL row for the sum record.

God of war 3 pcsx2 iso download free. • Tekan alt+enter untuk mode full screen dan windows. • Jika mengalami error, instal.

What’s your number? Many people living close to wind turbines become ill, possibly from 'Wind Turbine Sickness'. A judge (I think it was in Australia) recently ruled that this should be taken into account for siting of wind turbines no matter whether this illness is real or imaginary, either way it causes distress. Wind turbines are also believed to kill many more birds and bats than previously realised. The amount of electricity produced by wind turbines can also be very small an average of 2.3 MW/hour for the first six months of 2013 for metered accounts, this is not very much when you consider the vast sums of money paid for construction. Wind farms also spoil natural views and may inhibit tourism. Punk not dead An issue of even greater potential concern than meltwater lakes is the possible release of Arctic methane gas due to rising temperatures.

According to a study published last March in the journal Science, the permafrost under the East Siberian Arctic Shelf is perforated, causing large amounts of methane to leak into the atmosphere. Scientists say the release of even a small fraction of this potent greenhouse gas could trigger a precipitous rise in global temperatures with dire climatic consequences.

Yazike

Could I have a statement, please? Macroclimate Reform would not only ensure the improvement of economic stability in European markets, but it would also create lower debt ratios for peripheral states on the verge of collapse. The presence of an EU Treasury fueled by German-supported government bonds would offer structured fiscal policies and help to prevent global recession. These new fiscal regulations contain sovereign debt relief within the EU and promote inter-economic cooperation among sovereigns. Could you tell me the dialing code for? The thrillers, the children’s books for the eight-to-12-year-old market, the series of novels I once planned which define the condition of the postmodern, post-divorce, pre-menopausal woman, all unstarted because I haven’t the faintest idea how to write anything apart from biographies. I can’t even record my family history because I don’t know the first thing about my own family, such as my great-grandmother’s maiden name.