You'll want to implicitly unnest your array element. As an example
SELECT id, name, description
FROM articles as a, a.tags as single_tag
WHERE lang = "your lang value"
AND single_tag = "your tag value"
First, I implicitly unnested the array column tags to the column single_tag.
Second, I changed your where clause to an equality against the new single_tag column
Note: If multiple values in tags match your criteria, you can have the same row returned multiple times. You can address this by adding in a DISTINCT clause as long as none of the columns you are returning are arrays or structs. For example:
SELECT DISTINCT id, name, description
FROM articles as a, a.tags as single_tag
WHERE lang = "your lang value"
AND single_tag = "your tag value"
https://github.com/GoogleCloudPlatform/java-docs-samples/blob/master/spanner/cloud-client/src/main/java/com/example/spanner/SpannerSample.java
https://www.nextplatform.com/2017/02/15/googles-spanner-database-wont-well-clone/
Google luminary Eric Brewer, who is vice president of infrastructure at Google and who helped create many of the data services at the search engine giant, coined the CAP Theorem back in 1998 and the ideas were developed by the database community in the following years. The gist of CAP Theorem is that all distributed databases have to worry about three things – consistency, availability, and partition tolerance – and no matter what you do, you can only have no more than two of these properties being fully implemented at any time in the datastore or database
With Spanner, after a decade of work, Google has been able to achieve this. (You can read all about Spanner in the paper that Google release back in October 2012.) Part of the reason why Google can do this is because it has developed a sophisticated timestamping scheme for the globally distributed parts of Spanner that creates a kind of universal and internally consistent time that is synchronized by Google’s own network and is not dependent on outside services like the Network Time Protocol (NTP) that is used by servers to keep relatively in synch. Google needed a finer-grained control of timestamping with Spanner, so it came up with a scheme based on atomic clocks and GPS receivers in its datacenters that could provide a kind of superclock that spanned all of its datacenters, ordering transactions across the distributed systems. This feature, called TrueTime by Google, is neat, but the real thing that makes Google’s Spanner work at the speed and scale that it does is the internal Google network that lashes those datacenters to the same heartbeat of time as it passes.
