MarginaliaSearch/code/common/linkdb/readme.md

## Document Database

The document database contains information about links,
such as their ID, their URL, their title, their description,
and so forth.

The document database is a sqlite file.  The reason this information
is not in the MariaDB database is that this would make updates to
this information take effect in production immediately, even before
the information was searchable.

* [DocumentLinkDbWriter](java/nu/marginalia/linkdb/docs/DocumentDbWriter.java)
* [DocumentLinkDbLoader](java/nu/marginalia/linkdb/docs/DocumentDbReader.java)


## See Also

The database is constructed by the [loading-process](../../processes/loading-process), and consumed by the [index-service](../../services-core/index-service).
(*) Replace EC_DOMAIN_LINK table with files and in-memory caching The EC_DOMAIN_LINK MariaDB table stores links between domains. This is problematic, as both updating and querying this table is very slow in relation to how small the data is (~10 GB). This slowness is largely caused by the database enforcing ACID guarantees we don't particularly need. This changeset replaces the EC_DOMAIN_LINK table with a file in each index node containing 32 bit integer pairs corresponding to links between two domains. This file is loaded in memory in each node, and can be queried via the Query Service. A migration step is needed before this file is created in each node. Until that happens, the actual data is loaded from the EC_DOMAIN_LINK table, but accessed as though it was a file. The changeset also migrates/renames the links.db file to documents.db to avoid naming confusion between the two. 2024-01-08 14:53:13 +00:00			`## Document Database`

			`The document database contains information about links,`
(docs) Update the documentation up-to-date information 2023-09-14 09:33:36 +00:00			`such as their ID, their URL, their title, their description,`
			`and so forth.`

(*) Replace EC_DOMAIN_LINK table with files and in-memory caching The EC_DOMAIN_LINK MariaDB table stores links between domains. This is problematic, as both updating and querying this table is very slow in relation to how small the data is (~10 GB). This slowness is largely caused by the database enforcing ACID guarantees we don't particularly need. This changeset replaces the EC_DOMAIN_LINK table with a file in each index node containing 32 bit integer pairs corresponding to links between two domains. This file is loaded in memory in each node, and can be queried via the Query Service. A migration step is needed before this file is created in each node. Until that happens, the actual data is loaded from the EC_DOMAIN_LINK table, but accessed as though it was a file. The changeset also migrates/renames the links.db file to documents.db to avoid naming confusion between the two. 2024-01-08 14:53:13 +00:00			`The document database is a sqlite file. The reason this information`
(docs) Update the documentation up-to-date information 2023-09-14 09:33:36 +00:00			`is not in the MariaDB database is that this would make updates to`
			`this information take effect in production immediately, even before`
			`the information was searchable.`

Clean up documentation and rename `domain-links` to `link-graph` 2024-02-28 10:40:11 +00:00			`* [DocumentLinkDbWriter](java/nu/marginalia/linkdb/docs/DocumentDbWriter.java)`
			`* [DocumentLinkDbLoader](java/nu/marginalia/linkdb/docs/DocumentDbReader.java)`
(*) Replace EC_DOMAIN_LINK table with files and in-memory caching The EC_DOMAIN_LINK MariaDB table stores links between domains. This is problematic, as both updating and querying this table is very slow in relation to how small the data is (~10 GB). This slowness is largely caused by the database enforcing ACID guarantees we don't particularly need. This changeset replaces the EC_DOMAIN_LINK table with a file in each index node containing 32 bit integer pairs corresponding to links between two domains. This file is loaded in memory in each node, and can be queried via the Query Service. A migration step is needed before this file is created in each node. Until that happens, the actual data is loaded from the EC_DOMAIN_LINK table, but accessed as though it was a file. The changeset also migrates/renames the links.db file to documents.db to avoid naming confusion between the two. 2024-01-08 14:53:13 +00:00

			`## See Also`

Clean up documentation and rename `domain-links` to `link-graph` 2024-02-28 10:40:11 +00:00			`The database is constructed by the [loading-process](../../processes/loading-process), and consumed by the [index-service](../../services-core/index-service).`