How Tencent uses Postgres-XC for their high volume WeChat payment system

Track: Use Cases

Jasonys Li

April 20, 2016, 2:00PM - 2:50PM


Tencent, based in China, is one of the world's largest companies in the social networking space. This talk discusses how Tencent modified the code of Postgres-XC to meet their internal payment system requirements, including:

1. Scaling out while minimizing service interruption

With data retention of more than 5 years and tens of millions of new invoices per day, Tencent needs to scale out while queries are still running.

2. Optimizing query performance on ordered results

Queries must be fast. To sort and limit from 90 million rows within few seconds, a special sorting method was created to handle this.

3. Handling data skew across nodes

Some WeChat users have much more data than others, causing data skew. We added a special data policy to handle this situation.

4. Parallel execution of SQL and optimization

While Postgres-XC and Postgres-XL process in parallel across nodes, Tencent also added parallelization within the same node for the following operations:

a. Sequential scan
b. Hash Join
c. Nested Loop
d. Hash Aggregate
e. Sort Aggregate

5, High Availability across IDCs and cities

With real time invoice querying, High Availability with real time recovery was required

6. Using standby datanodes to provide read-only query capability, for workload optimization

About the Speaker

Jasonys Li works at Tencent Company, the biggest Internet company in China. Since 2014 Jason has been working on Postgres-XC adding custom features for their private version. Jason previously worked at Huawei from 2009 to 2013, developing an internal version of PostgreSQL.

Come Join Us!

Tickets for PGConf US 2016 on April 18-20, 2016 are available through EventBrite.   The first day, April 18, is dedicated to training sessions and the regulated industry summit. Trainings must be purchased as separate tickets and are only for those individual trainings. A "Regular Admission" ticket will give you access to the main conference on April 19th and 20th, the Regulated Industry Summit on April 18th, and the 20th Anniversary Party on April 19th.  We also have tickets provided for attending only certain events, such as the Regulated Industry Summit or the 20th Anniversary Party.

If you are a student and interested in attending PGConf US 2016, we are offering a discount rate of $49 for admission. Please email to register. You must be an active student at the time of the conference.

PGConf US 2016 is hosted by the United States PostgreSQL Association, which is a registered 501(c)(3). All ticket sales go directly to the program of PGConf US 2016 and any proceeds are used for the ongoing activities of the United States PostgreSQL Association, which include sponsoring PostgreSQL meetup groups, providing educational materials for PostgreSQL, and sponsoring speakers to discuss PostgreSQL at various events.

If you have any questions, please reach out to us at

PGConf US 2016 would not take place without the generous support from our sponsors.





Hosted By

Contact info

If you have any questions, comments, concerns, please feel free to contact us using the information below.