JAMES-2586 Optimize some postgres query

[vttranlina]

1. JAMES-2586 Optimize query increase/decrease for Quota Current Value

The query to increase the current value of the quota is frequently executed. The current SQL query is as follows:

insert into quota_current_value (
  identifier,
  component,
  type,
  "current_value"
)
values (
  '$1',
  '$2',
  '$3',
  '$4'
)
on conflict on constraint "quota_current_value_primary_key"
do update
set
  "current_value" = ("quota_current_value"."current_value" + $5);

This query is verbose and incurs overhead due to constraint checking.

=> The reality is the INSERT statement should be executed only once during initialization, and subsequent operations should use the UPDATE statement.
=> James can handle the INSERT and UPDATE cases appropriately.

---

2. JAMES-2586 Add Index for Postgres Mailbox table

The query searches for mailbox.mailbox_name using LIKE: :

james-project/mailbox/postgres/src/main/java/org/apache/james/mailbox/postgres/mail/dao/PostgresMailboxDAO.java

Line 186 in 542e495

public Flux<PostgresMailbox> findMailboxWithPathLike(MailboxQuery.UserBound query) {

select *
from mailbox
where (
  mailbox_name like '$1'
  and user_name = '$2'
  and mailbox_namespace = '$3'
);

Although the mailbox table already has an index for the trio (MAILBOX_NAME, USER_NAME, MAILBOX_NAMESPACE), the LIKE "prefix%" query slows it down.

=> Create one more index for the composite (USER_NAME, MAILBOX_NAMESPACE)

result:
before

after

[vttranlina]

Just tested the (2) on staging
Before

After

26ms -> 0.1 ms 🚀