Hi Jaanai and Pedro, Any input for my example?
Thanks, Shawn On Thu, Dec 27, 2018, 12:34 Shawn Li <[email protected] wrote: > Hi Jaanai, > > Thanks for the input. So the encoding schema is not simple first come > first assigned (such as in my example: A.population -> 1, A.type -> 2; > B.zipcode -> 1, B.quality ->2)? In order to decode it, we will have to > use QualifierEncodingScheme class? The reason we want to use the column > mapping is because the improvement of query performance mentioned on > Phoenix website. We have tables with columns number between 100 to 200. > > Thanks, > Shawn > > On Thu, Dec 27, 2018 at 2:22 AM Jaanai Zhang <[email protected]> > wrote: > >> The actual column name and encoded qualifier number are stored in >> SYSTEM.CATALOG >> table, the field names are COLUMN_NAME(string) and COLUMN_QUALIFIER(binary) >> respectively, QualifierEncodingScheme can be used to decode/encode >> COLUMN_QUALIFIER, but this is a little complicated process. >> >> For your scenario, maybe use the original column is better. >> >> >> >> >> ---------------------------------------- >> Jaanai Zhang >> Best regards! >> >> >> >> Shawn Li <[email protected]> 于2018年12月27日周四 上午7:17写道： >> >>> Hi Pedro, >>> >>> Thanks for reply. Can you explain a little bit more? For example, if we >>> use COLUMN_ENCODED_BYTES = 1,How is the following table DDL converted >>> to numbered column qualifier in Hbase? (such as A.population maps which >>> number, B.zipcode Map to which number in Hbase) >>> >>> CREATE TABLE IF NOT EXISTS us_population ( >>> state CHAR(2) NOT NULL, >>> city VARCHAR NOT NULL, >>> A.population BIGINT, >>> A.type CHAR, >>> B.zipcode CHAR(5), >>> B.quantity INT CONSTRAINT my_pk PRIMARY KEY (state, city)); >>> >>> >>> Thanks, >>> Shawn >>> >>> On Wed, Dec 26, 2018 at 6:00 PM Pedro Boado <[email protected]> wrote: >>> >>>> Hi, >>>> >>>> Column mapping is stored in SYSTEM.CATALOG table . There is only one >>>> column mapping strategy with between 1 to 4 bytes to be used to represent >>>> column number. Regardless of encoded column size, column name lookup >>>> strategy remains the same. >>>> >>>> Hope it helps, >>>> >>>> Pedro. >>>> >>>> >>>> >>>> On Wed, 26 Dec 2018, 23:00 Shawn Li <[email protected] wrote: >>>> >>>>> Hi, >>>>> >>>>> Phoenix 4.10 introduced column mapping feature. There are four types >>>>> of mapping schema (https://phoenix.apache.org/columnencoding.html). >>>>> Is there any documentation that shows how to encode/map string column name >>>>> in Phoenix to number column qualifier in Hbase? >>>>> >>>>> We are using Lily Hbase indexer to do the batch indexing. So if the >>>>> column qualifier is number. We need find a way to decode it back to the >>>>> original String column name. >>>>> >>>>> Thanks, >>>>> Shawn >>>>> >>>>
