Cohort Builder - Technical Details -V2

The purpose of this document is to provide technical details of how the proposed https://sagebionetworks.jira.com/wiki/spaces/PD/pages/2730721508 might be built.

Setup

To help us understand all of the technical challenges for this project we built a toy example data model. This data model was designed to capture all of the technical challenges while remaining as simple and small as we could make it.

The data model is composed of three main building blocks:

FILE_VIEW- This represents a Synapse file view that contains all of the files within the scope of the project. Each row represents a single file. The metadata about each file is captured in the columns of this table. These files represent the entire pool of files that the end user can draw from.
PARTICIPANTS - This represents a Synapse table that contains one row per participant. The metadata about each participant is captured in the columns of this table. These participants represent the entire pool of candidate participants that the end user can draw from.
FILE_TO_PART - This is a Synapse table that maps files to participant. In the real data a single participant might be mapped to thousands of files, and vice versa.
MATERIAL - This table represents a materialized view that is the de-normalized join of the preceding three tables. It includes files that might not have any participants and vice versa. In the real world this table would be automatically indexed on all relevant columns. Note: A worst case for this table would be where each file is associated with each participant thereby resulting in a Cartesian product.

If you would like to try out the data model here is the ddl:

DROP DATABASE `COHORT`;
CREATE DATABASE `COHORT`;

USE `COHORT`;

CREATE TABLE IF NOT EXISTS `FILE_VIEW` (
	`ID` BIGINT NOT NULL,
    `NAME` varchar(256) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL,
    `TYPE` ENUM ('raw','proc') NOT NULL,
	`SIZE` BIGINT NOT NULL,
    `BEN_ID` BIGINT NOT NULL,
    PRIMARY KEY (`ID`)
);

CREATE TABLE IF NOT EXISTS `PARTICIPANTS` (
	`ID` BIGINT NOT NULL,
    `NAME` varchar(256) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL,
	`STAGE` ENUM('one','two'),
    `AGE` BIGINT NOT NULL,
    PRIMARY KEY (`ID`)
);

CREATE TABLE IF NOT EXISTS `FILE_TO_PART` (
	`FILE_ID` BIGINT NOT NULL,
	`PART_ID` BIGINT NOT NULL,
    PRIMARY KEY (`FILE_ID`, `PART_ID`)
);

INSERT INTO `FILE_VIEW` VALUES 
	(1,'f1','raw',100,111),
	(2,'f2','raw',200,111),
	(3,'f3','raw',300,111),
	(4,'f3','raw',400,111),
	(5,'f5','proc',100,111),
	(6,'f6','proc',200,111),
	(7,'f7','proc',300,222),
	(8,'f8','proc',400,222),    
	(9,'no participants','proc',100,111)
    ;

INSERT INTO `PARTICIPANTS` VALUES 
	(1,'P1','one',10),
    (2,'P2','one',20),
	(3,'P3','one',30),
    (4,'P4','one',40),
	(5,'P5','two',10),
    (6,'P6','two',20),
	(7,'P7','two',30),
    (8,'P4','two',40),
	(9,'no files','one', 18),
	(10,'few files','two', 30)
    ;
    
INSERT INTO `FILE_TO_PART` VALUES 
    # f1 to all
	(1,1),
	(1,2),
	(1,3),
	(1,4),
	(1,5),
    (1,6),
    (1,7),
    (1,8),
    # f2 to even
    (2,2),
	(2,4),
    (2,6),
    (2,8),
    # f3 to odd
	(3,1),
	(3,3),
	(3,5),
    (3,7),
    # f4 only stage one
    (4,1),
    (4,2),
    (4,3),
    (4,4),
    # f5 only stage two
    (5,5),
    (5,6),
    (5,7),
    (5,8),
    # f6 under20
	(6,1),
    (6,2),
    (6,5),
    (6,6),
	# f7 over 20
	(7,3),
    (7,4),
    (7,7),
    (7,8),
	# f8 to all
	(8,1),
	(8,2),
	(8,3),
	(8,4),
	(8,5),
    (8,6),
    (8,7),
    (8,8),
    # p10 only few files
    (2,10),
    (3,10),
	(5,10)
    ;

/* 
This table is the denormalized materialization of all of the data.
It includes all files including files with no particpants.  It also
incldues all participants, even those with no files.
*/
CREATE TABLE `MATERIAL`
# includes all files even those without participants
SELECT F.ID AS FILE_ID, F.NAME AS FILE_NAME, F.TYPE AS FILE_TYPE, F.BEN_ID AS FILE_BEN_ID, P.ID AS PART_ID, P.NAME AS PART_NAME, P.STAGE, P.AGE 
	FROM `FILE_VIEW` F LEFT JOIN `FILE_TO_PART` F2P ON (F.ID = F2P.FILE_ID) LEFT JOIN `PARTICIPANTS` P ON ( F2P.PART_ID =P.ID )
UNION
# Add all particpants that do not have any files
SELECT F.ID AS FILE_ID, F.NAME AS FILE_NAME, F.TYPE AS FILE_TYPE, F.BEN_ID AS FILE_BEN_ID, P.ID AS PART_ID, P.NAME AS PART_NAME, P.STAGE, P.AGE 
	FROM `FILE_VIEW` F JOIN `FILE_TO_PART` F2P ON (F.ID = F2P.FILE_ID) RIGHT JOIN `PARTICIPANTS` P ON ( F2P.PART_ID =P.ID ) WHERE F.ID IS NULL;

Full De-normalized Data

After running the above script we can start to query the data. For example here is the contents of the MATERIAL table:

select * from MATERIAL;

FILE_ID	FILE_NAME	FILE_TYPE	FILE_SIZE	FILE_BEN_ID	PART_ID	PART_NAME	STAGE	AGE

FILE_ID	FILE_NAME	FILE_TYPE	FILE_SIZE	FILE_BEN_ID	PART_ID	PART_NAME	STAGE	AGE
1	f1	raw	100	111	1	P1	one	10
1	f1	raw	100	111	2	P2	one	20
1	f1	raw	100	111	3	P3	one	30
1	f1	raw	100	111	4	P4	one	40
1	f1	raw	100	111	5	P5	two	10
1	f1	raw	100	111	6	P6	two	20
1	f1	raw	100	111	7	P7	two	30
1	f1	raw	100	111	8	P4	two	40
2	f2	raw	200	111	2	P2	one	20
2	f2	raw	200	111	4	P4	one	40
2	f2	raw	200	111	6	P6	two	20
2	f2	raw	200	111	8	P4	two	40
2	f2	raw	200	111	10	few files	two	30
3	f3	raw	300	111	1	P1	one	10
3	f3	raw	300	111	3	P3	one	30
3	f3	raw	300	111	5	P5	two	10
3	f3	raw	300	111	7	P7	two	30
3	f3	raw	300	111	10	few files	two	30
4	f3	raw	400	111	1	P1	one	10
4	f3	raw	400	111	2	P2	one	20
4	f3	raw	400	111	3	P3	one	30
4	f3	raw	400	111	4	P4	one	40
5	f5	proc	100	111	5	P5	two	10
5	f5	proc	100	111	6	P6	two	20
5	f5	proc	100	111	7	P7	two	30
5	f5	proc	100	111	8	P4	two	40
5	f5	proc	100	111	10	few files	two	30
6	f6	proc	200	111	1	P1	one	10
6	f6	proc	200	111	2	P2	one	20
6	f6	proc	200	111	5	P5	two	10
6	f6	proc	200	111	6	P6	two	20
7	f7	proc	300	222	3	P3	one	30
7	f7	proc	300	222	4	P4	one	40
7	f7	proc	300	222	7	P7	two	30
7	f7	proc	300	222	8	P4	two	40
8	f8	proc	400	222	1	P1	one	10
8	f8	proc	400	222	2	P2	one	20
8	f8	proc	400	222	3	P3	one	30
8	f8	proc	400	222	4	P4	one	40
8	f8	proc	400	222	5	P5	two	10
8	f8	proc	400	222	6	P6	two	20
8	f8	proc	400	222	7	P7	two	30
8	f8	proc	400	222	8	P4	two	40
9	no participants	proc	100	111	NULL	NULL	NULL	NULL
NULL	NULL	NULL	NULL	NULL	9	no files	one	18

Two Perspectives

While the MATERIAL table contains all of the data, it would be challenging to use in its raw form. To improve usability, the data is exposed as two separate perspectives of the data:

Participants-with-aggregated-files - The results of this query is such that each row represents a single participant, including columns for the participant’s metadata. The results also include additional columns that contain file aggregation data for each participant.
Files-with-aggregated-participants - The results of this query is such that each row represents a single file, including columns for the file’s metadata. The results also include additional columns that contain participant aggregation data for each file.

The unfiltered participants-with-aggregated-files would look like:

WITH
	P2F AS (
		SELECT 
			PART_ID,
			MAX(PART_NAME) AS PART_NAME,
			MAX(STAGE) AS STAGE,
			MAX(AGE) AS AGE,
			COUNT(FILE_ID) AS FILE_COUNT,
			SUM(CASE FILE_TYPE WHEN 'raw' THEN 1 ELSE 0 END) AS RAW_FILES,
			SUM(CASE FILE_TYPE WHEN 'proc' THEN 1 ELSE 0 END) AS PROC_FILES,
            MAX(FILE_SIZE) AS `MAX_SIZE`,
			MIN(FILE_SIZE) AS `MIN_SIZE`,
			GROUP_CONCAT(DISTINCT FILE_ID) AS FILE_IDS
				FROM MATERIAL WHERE PART_ID IS NOT NULL GROUP BY PART_ID ORDER BY PART_ID ASC
	),
    AGG AS (
		SELECT 
			PART_ID, PART_NAME, STAGE, AGE, FILE_COUNT,
			JSON_OBJECT('raw', RAW_FILES, 'proc', PROC_FILES) as FILE_TYPE,
			JSON_OBJECT('max', `MAX_SIZE`, 'min', `MIN_SIZE`) as FILE_SIZE,
			FILE_IDS    
				FROM P2F
	)
SELECT * FROM AGG;

PART_ID	PART_NAME	STAGE	AGE	FILE_COUNT	FILE_TYPE	FILE_SIZE	FILE_ID

PART_ID	PART_NAME	STAGE	AGE	FILE_COUNT	FILE_TYPE	FILE_SIZE	FILE_ID
1	P1	one	10	5	{"raw": 3, "proc": 2}	{"max": 400, "min": 100}	1,3,4,6,8
2	P2	one	20	5	{"raw": 3, "proc": 2}	{"max": 400, "min": 100}	1,2,4,6,8
3	P3	one	30	5	{"raw": 3, "proc": 2}	{"max": 400, "min": 100}	1,3,4,7,8
4	P4	one	40	5	{"raw": 3, "proc": 2}	{"max": 400, "min": 100}	1,2,4,7,8
5	P5	two	10	5	{"raw": 2, "proc": 3}	{"max": 400, "min": 100}	1,3,5,6,8
6	P6	two	20	5	{"raw": 2, "proc": 3}	{"max": 400, "min": 100}	1,2,5,6,8
7	P7	two	30	5	{"raw": 2, "proc": 3}	{"max": 400, "min": 100}	1,3,5,7,8
8	P4	two	40	5	{"raw": 2, "proc": 3}	{"max": 400, "min": 100}	1,2,5,7,8
9	no files	one	18	0	{"raw": 0, "proc": 0}	{"max": null, "min": null}
10	few files	two	30	3	{"raw": 2, "proc": 1}	{"max": 300, "min": 100}	2,3,5

The unfiltered files-with-aggregated-participants would look like:

FILE_ID	FILE_NAME	FILE_TYPE	FILE_SIZE	PART_COUNT	PART_STATE	PART_AGE	PART_ID

FILE_ID	FILE_NAME	FILE_TYPE	FILE_SIZE	PART_COUNT	PART_STATE	PART_AGE	PART_ID
1	f1	raw	100	8	{"one": 4, "two": 4}	{"max": 40, "min": 10}	1,2,3,4,5,6,7,8
2	f2	raw	200	5	{"one": 2, "two": 3}	{"max": 40, "min": 20}	2,4,6,8,10
3	f3	raw	300	5	{"one": 2, "two": 3}	{"max": 30, "min": 10}	1,3,5,7,10
4	f3	raw	400	4	{"one": 4, "two": 0}	{"max": 40, "min": 10}	1,2,3,4
5	f5	proc	100	5	{"one": 0, "two": 5}	{"max": 40, "min": 10}	5,6,7,8,10
6	f6	proc	200	4	{"one": 2, "two": 2}	{"max": 20, "min": 10}	1,2,5,6
7	f7	proc	300	4	{"one": 2, "two": 2}	{"max": 40, "min": 30}	3,4,7,8
8	f8	proc	400	8	{"one": 4, "two": 4}	{"max": 40, "min": 10}	1,2,3,4,5,6,7,8
9	no participants	proc	100	0	{"one": 0, "two": 0}	{"max": null, "min": null}

Expected User Experience

In a previous version of this document we considered exposing these perspectives to users by requiring UI engineers generate the SQL needed to generate them. If you expanded the query sections for these two perspectives you would notice that the SQL is non-trivial. To sort and/or filter on these perspectives (covered in a later section), adds yet another layer of complexity.

If you look at a complex table/view with multiple facets in any portal or the Synapse UI, you will see a set of fairly standard controls on the left-hand-side panel and in the columns headers. Users are able to filter and sort the results by manipulating theses controls. Typically, the UI code does not need to directly parse or generate SQL when these controls change. Instead, the UI can pass model objects that describe the filtering and sorting to the Synapse query service, which then manipulate the SQL on the caller’s behalf. This basic functionally works for all table/view features including:

File Views
Tables
Materialized Views
Submission Views (challenges)

So rather than pushing the complexity to the UI, it would be better if these perspectives behaves like any other Synapse table/view. Parsing and SQL manipulation should not be required. This means that the perspectives should behave as if they are the simple tables they appear to be. So, our new design attempts to hide most of the complexity without losing any of the functionality. We would also like the resulting feature to be generic enough to work for other (non-cohort-builder) use cases.

Perspective Details

If we want to treat these perspectives as simple tables, what is the minimum information needed to describe them? In this section we will attempt to answer this questions by focusing on the files-to-participant-perspective. Our assumption is that both perspectives are two variations of the same theme, so anything that works for one, should work for the other.

Schema

The UI utilizes the schema of a table/view to determine how it should be rendered and controlled. Specifically, the column types define how each cell should be rendered/sorted. While each column’s facet types determine which controls should be include in headers and the left-hand-side pane of the UI.

When you define a materialized view (MV) in Synapse you do not directly define its schema. Instead, the schema is automatically determined by the select-statement of the MV’s defining SQL. For example, if a MV contains a join of two tables, the select statement will typically refer to the columns of each of the tables. So for MVs, we automatically inherit the ColumnModel of any selected column from its source table. While this simple assumption might work for most MV use cases it does not work well for aggregation or any other type of “derived column”.

For example, the PART_COUNT column does not exist in the source MATERIAL table, instead it is a derived aggregation. Count is a simple case that always returns an integer so it should be safe to assume a column type of INTEGER. However, what about the other three aggregate columns: PART_STAGE, PART_AGE, and PART_ID? Each contains different types of data.

The following is an example of what the files-to-participant-perspective schema could be:

id	name	columnType	enumValues	facetType	agg_functions

id	name	columnType	enumValues	facetType	agg_functions
11	FILE_ID	INTEGER
22	FILE_NAME	STRING
33	FILE_TYPE	STRING	[raw,proc]	enumeration
44	FILE_SIZE	INTEGER		range
55	PART_COUNT	INTEGER		range
66	PART_STAGE	JSON	[one,two]	aggregate-enumeration
77	PART_AGE	JSON		aggregate-range	min,max
88	PART_ID	INTEGER_LIST

The first five columns (11,22,33,44,55) and the last (88) are all existing column types supported by both the clients and server. This means the UI should be able to treat those columns exactly like any other column of the same type. However, PART_STAGE (76) and PART_AGE (77) include new types definitions. We will talk about these new types next.

Column TypeJSON

Technically, the aggregate statistics for the PART_STAGE are gathered in two separate columns using the following in the the SQL select:

In fact, we need a column for each distinct enumeration value. So an enumeration with ten possible values would require ten columns to generate the appropriate statistics. In the UI design for the cohort builder, this type of aggregate enumeration data is shown as a single complex column. This is a nice, compact, way to look at a lot of data. One way to represent such complexity is to combine all of the data for a single cell into JSON.

MySQL provides JSON specific functions that we can use to combine multiple column into a single JSON column. For example, the following was used to recombine the two columns for ‘one’ and ‘two’ into a single column of JSON:

MySQL also provides JSON specific functions that can be used for both sorting and filtering on contents of JSON columns. For example, let’s assume the user wants to filter on the FILE_TYPE column as follows:

This filter is syntactic sugar for:

We can also use a similar syntax for sorting:

Which is syntactic sugar for:

As we can see, having a new column type of JSON, enables us to solve complex problems for columns with complex data. This column type will likely prove useful for other non-cohort-builder use cases.

Aggregate Functions

The basic idea for this column type metadata was to provide a list of the aggregate functions that should be provided for an aggregate numeric column like PART_AGE. In our example schema column ID 77 has: min,max. This indicates that we should gather both the min and max for this column. Other options might include: sum, avg, count, count(distinct), std.

Is there a better place to capture this information? Should we just hard-code it to min and max?

Before we describe the new facet types let’s quickly review our two existing facet types:

facetType	Applies To	Statistics	Filtering

facetType	Applies To	Statistics	Filtering
enumeration	Columns with one or more enumValue.	Provides the total count of each occurrence of each enumeration value with the current query filter applied.	When an enumeration value is “selected' all rows with non-selected enumeration values are excluded from the result.
range	Numeric columns	Provides the min and max of a numeric column with the current query filter applied.	The user provides an upper and lower bounds. This adds a filter to the numeric column such that the values are between lower and upper (inclusive).

To define this facet type, let’s try to define what type of statistics and filtering controls we would want to provide for the PART_STAGE column.

Let’s start with the statistics that would be shown for the entire table on the left-hand-side in the UI:

value	min	max

value	min	max
one	0	4
two	0	4

Given these statistics a user might want to do a “range” filter such as:

You could image the controls for such a facet would have two range sliders; one for each stage enumeration value.

To define this facet type, let’s try to define what type of statistics and filtering controls we would want to provide for the PART_AGE column.

Since each row contains a min and a max, the logical statistics for the entire table seem to be the min of the mins, max of the mins….

value	min	max

value	min	max
min	10	30
max	20	40

These statistics seem similar to aggregate-enumeration. Should they really be two separate types?

Filtering Before Aggregation

So far, we have only discussed applying filters to aggregated columns. Such filters must be applied after the aggregation results are calculated. However, the main use case requires some runtime filtering to occur before aggregation is applied.

For example, a user might start with the participants-with-aggregated-files perspective and narrow down their selection of participant IDs to: 2, 4, 5, & 7.

They then will want to apply their selection of participant IDs as a filter to files-with-aggregated-participants perspective. This filter must change the aggregated participant data. This means the filter must be applied before aggregation occurs.

Here is what the results look like with this filter applied:

FILE_ID	FILE_NAME	FILE_TYPE	FILE_SIZE	PART_COUNT	PART_STATE	PART_AGE	PART_ID

FILE_ID	FILE_NAME	FILE_TYPE	FILE_SIZE	PART_COUNT	PART_STATE	PART_AGE	PART_ID
1	f1	raw	100	4	{"one": 2, "two": 2}	{"max": 40, "min": 10}	2,4,5,7
2	f2	raw	200	2	{"one": 2, "two": 0}	{"max": 40, "min": 20}	2,4
3	f3	raw	300	2	{"one": 0, "two": 2}	{"max": 30, "min": 10}	5,7
4	f3	raw	400	2	{"one": 2, "two": 0}	{"max": 40, "min": 20}	2,4
5	f5	proc	100	2	{"one": 0, "two": 2}	{"max": 30, "min": 10}	5,7
6	f6	proc	200	2	{"one": 1, "two": 1}	{"max": 20, "min": 10}	2,5
7	f7	proc	300	2	{"one": 1, "two": 1}	{"max": 40, "min": 30}	4,7
8	f8	proc	400	4	{"one": 2, "two": 2}	{"max": 40, "min": 10}	2,4,5,7

Notice, the previous unfiltered results for file:1 had a PART_COUNT=8, while the filtered results have a PART_COUNT=4.

If the aggregation results did not need to change at runtime, then we could simply use a materialized view as a solution to the entire problem. For example, we could pre-build a MV with millions rows of “static” aggregate data. End users could query this “static” data at runtime without any problems.

On the other hand, if the user’s runtime selections can change the aggregation results, then materialization does not help. In fact, it would require that we rebuild millions of material rows with each click. This means we need a solution that will support filtering both before and after aggregation without materialization.

Aggregate View

We are proposing adding a new entity Type called AggregateView. Like a MaterializedView, an AggregateView would be configured by setting its defining SQL. However, that is where the similarities end. An AggregateView is not a materialization. This means that we do not create an actual table in the database for this view. Instead, an AggregateView provides a simple, table like, layer of of abstraction over a complex aggregation query. To better understand this concept, lets show how we would use an AggregateView to create the files-to-participant-perspective.

Creating an AggregateView

Let’s assume we have already created our desired ColumnModels according to the above schema, with the resulting column IDs: 11,22,33,44,55,66,77,88. We can now create a new AggregateView with the following definingSQL:

Next we will cover each line of this SQL.

The first thing to notice is that the SQL is an aggregation as it contains a GROUP BY (line:11). Specifically, we are grouping by all of the relevant columns of the FILE_VIEW.

Next, at line:2 we have CAST(FILE_ID AS 11), which defines the first column of the perspective. This line is simply casting the FILE_ID as column ID: 11. In other words, line 2 tells Synapse to treat the first column of the resulting table as type INTEGER with the name FILE_ID (see: ID 11). Note: Since FILE_ID is part of the group by, we are not required apply an aggregation function to it. Any column that is not part of the group by must have some type of aggregation functions.

Lines 3-5 are similar to line:2 where the rest of the file’s columns are cast to their respective column model IDs.

At line:6 we have our first aggregation function COUNT(PART_ID). Since a single file ID could map to many participants, we need an aggregation function define how to handle the “many”. In this case we simply want the count. We then cast the resulting count as column ID=55, which has a simple INTEGER type.

At line:7 we have a new function: AGG_EXPAND(STAGE AS 66) called AGG_EXPAND. This function call is syntactic sugar that tells Synapse to do the following:

Add a column for each value of the enumeration with a case statement that will count the occurrences of each.
In the next layer of the CTE, recombine all of the expanded columns into a single column of JSON.
In the final layer of the CTE, cast the resulting JSON as column ID=66.

At line:8 we have AGG_EXPAND(AGE AS 77) which will do a similar expansion to the previous case. This expansion will create a column for each aggregate function defined in column ID=77.

Finally, at line:9 we have CAST(GROUP_CONCAT(DISTINCT PART_ID) AS 88). The group concat function will create a comma separated list of all of the PART_IDs that match each file. The results are then cast to column ID=88 which is of type STRING_LIST. This means this column will behave similar to other string list columns in Synapse.

Querying an AggregateView

Once we have defined our AggregateView we can run a query against it like any other table/view in Synapse. Let’s assume that we created the AggregateView using the defining SQL from the previous section. The resulting AggregateView is then assigned syn123. If we get the schema for syn123, we would see its column IDs are: 11,22,33,44,55,66,77,88.

To query this view we could simply send the following to the query service:

The results of this query would be exactly the same as the unfiltered files-with-aggregated-participants table shown above.

So how does that work exactly? Basically, when the user provides select * from syn123 at runtime, we run the following query on their behalf:

The above SQL is actually a combination of the syn123’s defining SQL and the runtime query (select * from syn123). Specifically, the inner query of the common table expression (CTE) (lines:3-14) are an expansion of the defining SQL. While the runtime query is transformed into the outer query of the CTE (line:15). In essence, the user is querying what appears to be a simple table.

A real runtime query transformation would be more complex but basic principals would still apply. For example, since our MATERIAL table includes files, the transformation process would include adding a row-level-filter to hide rows where the user lacks the read permission. This type of query manipulation is already common for existing Synapse tables/views.

In the next section, we will show how runtime filtering and sorting would be applied using a few examples.

First, lets assume that the user wants to only see rows where PART_STAGE ‘one’ is greater than two:

For this query the first 14 lines of the above query would remain the same, while the last line (line:15) would become:

A sorting example would be similar. For example to sort on PART_STAGE ‘two’ asc:

Again we would only need to change the last line the CTE to be:

The above filters/sorting applied to the aggregation results. We still need to cover the case where the user is requesting a filter before aggregation. We will use the same example filter where the user per-selected participant IDs to: 2, 4, 5, & 7:

Here we have defined a new function called pre_agg() which is syntactic sugar that means apply this filter before aggregation. So rather than apply the filter at the end of the CTE (line:15) it is added to the inner layer of the CTE (line:13).

The key to this entire design is that there is always a one-to-one translation for anything in the both the provide defining SQL and runtime queries.

New Features

The implementation plan is to divide the work into two phases:

Phase One - Add support for CTE, CASE Statement, JSON columns/functions to the runtime query services. At the end of this phase a user should be able to run this type of query against any Synapse table/view:
Phase Two: Add AggregateViews plus the new aggregate facet types as syntactic sugar that will be expanded to the full SQL from phase one at runtime.

To see the full list of features needed to make this design work see the epic:

PLFM-7789 - Getting issue details... STATUS

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